ABSTRACT This paper describes the flight test of a mounted touchscreen device in a UH-60 helicopter. The device assists crew chiefs in their fuel management tasks and provides situational awareness information regarding the route/flight plan, map data, external camera displays, publications and aircraft system information. The touchscreen tested was a 10.5" display and used Projected Capacitive for touch input. It was surrounded by 28 bezel switches. Eight current crew chiefs performed tasks using the device in flight. The participants wore gloves. Flight test evaluation results show that the subjects used and preferred the bezel switches over soft buttons on the touchscreens. Results also show that 16% percent of touchscreen presses required multiple presses to register the touch. Vibration did not appear to cause a problem with using the touchscreen. Gloves did present a problem in using the Projected Capacitive touchscreen.

Schutte, Paul

Effect of E-Modulus Variation on Springbackand a Practical Solution

2018-01-06304/3/2018

Springback affects the dimensional accuracy and final shape of stamped parts. Accurate prediction of springback is necessary to design dies that produce the desired part geometry and tolerances. Springback occurs after stamping and ejection of the part because the state of the stresses and strains in the deformed material has changed. To accurately predict springback through finite element analysis, the material model should be well defined for accurate simulation and prediction of stresses and strains after unloading. Despite the development of several advanced material models that comprehensively describe the Bauschinger effect, transient behavior, permanent softening of the blank material, and unloading elastic modulus degradation, the prediction of springback is still not satisfactory for production parts. Dies are often recut several times, after the first tryouts, to compensate for springback and achieve the required part geometry. In this study, the effect of Young’s modulus (E-modulus) on springback is investigated. Current challenges in determination of E-modulus through tensile test are discussed and a practical method is proposed which has the potential to improve springback prediction after the first die tryout. In this method, the unloading elastic modulus is adjusted by measuring the springback of the part produced during the first tryout and comparing it with finite element (FE) simulation results. The unloading elastic modulus obtained from this method is called the “apparent E-modulus”. This method is applied to three bending cases: a wipe bending, a U-drawing, and a 3-D crash forming of an actual production part. Results show that the springback can be predicted fairly accurate using the apparent E-modulus and a simple isotropic hardening model.

Fallahiarezoodar, Ali, Goertemiller, Cliff, Katre, Aanandita, Altan, Taylan

Replacing Press Hardenable Steel with 980 MPa Generation 3 Steel for Automotive Pillars

2018-01-01174/3/2018

Press hardenable ultra high strength steel (UHSS) is commonly used for automotive components to meet crash requirements with minimal mass addition to the vehicle. Press hardenable steel (PHS) is capable of forming complex geometries with deep sections since the forming takes place at elevated temperatures up to 900 degrees Celsius (in the Austenitic phase). This forming process is known as hot-stamping. The most commonly used PHS grade is often referred to as PHS1500. After hot-stamping, it is typically required to have a yield strength greater than 950 MPa and a tensile strength greater than 1300 MPa. Most automotive design and material engineers are familiar with PHS, the hot-stamping process, and their capabilities. What is less known is the capability of 3rd Generation advanced high strength steels (AHSS) which are cold stamped, also capable of forming complex geometry, and are now in the process of, or have recently completed, qualification at most automotive manufacturers. This paper will show that U. S. Steel’s Generation 3 steel with 980 MPa minimum tensile strength (980GEN3) has comparable crash performance to PHS1500 when used for automotive body-in-white (BIW) Pillars in a sedan. This paper will also show that these 980GEN3 BIW Pillars can achieve the same complex geometry as PHS1500, that the springback can be predicted and controlled, and that prototype parts can be assembled into a vehicle build and physically crashed without issues. Furthermore, correlation between cold stamped 980GEN3 BIW Pillars and forming simulation results will also be discussed.

McKune, Paul, Khutorsky, Alex, Butala, Kapil

Effects of AHSS Sheared Edge Conditions on Crash Energy Absorption in Component Bend Test

2018-01-01134/3/2018

Edge fracture of advanced high strength steels (AHSS) can occur in both the stamping process and the crash event. Fracture due to poor sheared edge conditions in the stamping process was reduced with a recently developed optimal shearing process for AHSS. Currently, the improvement in the energy absorption due to the improved edge condition during crashes performed under different loading conditions had not been closely verified. The purpose of this study is to design and build a miniature component of AHSS and a three-point bending test for investigating the influence of various conditions of the sheared edge on the energy absorption in crashes. AHSS including DP600, TRIP780, DP980 and DP1180 were selected in the study. A small channel component was developed and fabricated using DP980 to simulate key features of the B-pillar. The exposed non-constrained, as-sheared edge was subject to stretch bending forces in three-dimensional space during the three-point bending test. Two bottom rollers equipped in the three-point bending test allowed the test specimen to bend freely without generating extra friction force between the test material and tooling. Previously developed shearing parameters were fine-tuned for generating the test specimen on the flexible shearing machine and then compared to the specimens made by water jet cutting and laser cutting. A life cycle analysis was also conducted by FEA to evaluate the new design of the shear blade. The experiment results indicate the improvement of the sheared edge conditions can also increase the material energy absorption in crashes. The laser cut sample has the best energy absorption capability, while the conventional cutting edge shows the worst. In addition to the three-point bending test, a wedge bend test was conducted on the flat sample and reached a similar energy absorption trend as in the component bend test. The wedge bend test on flat sample is recommended for baseline comparison in material bendability and crash energy absorption capability among different advanced high strength steels.

Shih, Hua-Chu, Chen, Guofei

Spring Assistance (Energy-Swing) in an Electro Mechanical Brake

2017-01-25179/17/2017

On Electro-Mechanical Brakes (EMB) spring-support can be necessary for releasing the brake without electrical energy. Advantageous brake-configurations can make use of the spring over the whole actuation range during engage and release. Such optimized spring support is known as “energy-swing. Under loss-less conditions the spring force could be in permanent equilibrium with the force required to press the pad, i.e. the brake could be controlled without actuation energy. In reality this will not be fully achievable as actuation losses and different operational conditions need to be covered. Still, significant advantages can be gained. The EMB of Vienna Engineering (VE) fulfills a key condition for energy-swing as it facilitates using the spring for engage- and release-support. Car brakes must release automatically when power is off. Consequently, spring-induced engage-support must always be smaller than release-forces and release-support must ensure overcoming mechanical resistance. The VE-EMB can fulfill the requirements while maximizing the benefits by introducing a cam /rocker mechanism. With realistic assumptions of losses, tolerances and operational influences the potential of the mechanism in terms of saving actuation energy, reducing actuator motor power and actuation timing improvement must be questioned. Besides, the related increase of complexity needs to be addressed. This paper discusses the issues by comparing a VE-EMB without spring, the cam-rocker design and the simpler but less configurable lever-pushing method.

Putz, Michael Herbert, Zipper, Thomas

Extensional Rheology: New Dimension of Characterizing Automotive Fluids

2017-01-03643/28/2017

This paper describes the basic principles of extensional rheometry, and the successful application to a variety of automotive fluids, including gear lubricants, paints, and forming lubricants. These fluids are used under very complex flow fields containing strong extensional (elongational) components. While exact derivation of extensional viscosities involves sophisticated theories, the measurement of liquid filament break-up time can provide fruitful information. Gear lubes showed different break-up time according to the kinematic viscosities. Addition of viscosity modifier (acrylic copolymer) significantly increased the breakup time, whereas surfactants had little effect. Clearcoat paint sample increased the breakup time, perhaps due to the deterioration. The waxy stamping lubricant showed remarkable change in the extensional properties as the temperature is raised. The extensional data obtained showed the promise of the technique to understand the performance of these fluids in working conditions (e.g. spraying, coating, and stamping).

Ohtani, Hiroko, Ellwood, Kevin, Pereira, Gustavo, Chinen, Thiago, Selvasekar, Siddharthan

An Optimization Model for Reallocating Stamped Parts

2017-01-02443/28/2017

We describe an optimization model developed by Ford Motor Company to reallocate stamped parts between facilities when business conditions change. How can the business meet new targets when demand starts to exceed existing capacity? Likewise, how can it respond when demand is lower than expected? Sometimes the business can reduce costs by transferring production to a different location or by outsourcing parts. We describe in this paper how mathematical optimization can identify solutions that balance both logistical and outsourcing costs. We explain the algorithm and demonstrate with a small example how it recommends sourcing plans that minimize cost.

Lyon, Joshua, Park, Junheung, Fradkin, Yakov, Tornabene, Jeff

Modeling and Simulation of Compression Molding Process for Sheet Molding Compound (SMC) of Chopped Carbon Fiber Composites

2017-01-02283/28/2017

Compression molded SMC composed of chopped carbon fiber and resin polymer which balances the mechanical performance and manufacturing cost presents a promising solution for vehicle lightweight strategy. However, the performance of the SMC molded parts highly depends on the compression molding process and local microstructure, which greatly increases the cost for the part level performance testing and elongates the design cycle. ICME (Integrated Computational Material Engineering) approaches are thus necessary tools to reduce the number of experiments required during part design and speed up the deployment of the SMC materials. As the fundamental stage of the ICME workflow, commercial software packages for SMC compression molding exist yet remain not fully validated especially for chopped fiber systems. In the present study, SMC plaques are prepared through compression molding process. The corresponding simulation models are built in Autodesk Moldflow with the same part geometry and processing conditions as in the molding tests. The output variables of the compression molding simulations, including press force history and fiber orientation of the part, are compared with experimental data. Influence of the processing conditions to the fiber orientation of the SMC plaque is also discussed. It is found that generally Autodesk Moldflow can achieve a good simulation of the compression molding process for chopped carbon fiber SMC, yet quantitative discrepancies still remain between predicted variables and experimental results.

Li, Yang, Xu, Hongyi, Dahl, Jeffrey, Zeng, Danielle, Su, Xuming, Mirdamadi, Mansour, Chen, Zhangxing

An Investigation of Deformation Effects on Phase Transformation in Hot Stamping Processes

2016-01-03614/5/2016

To reduce the fuel consumption as well as to improve the crash safety of vehicles, the usage of hot stamping parts is increasing dramatically in recent years. Aisin Takaoka has produced hot stamping parts since 2001 and has developed various technologies related to Hot Stamping. In an actual hot stamping process, parts with insufficient strength could be produced sometimes at a prototyping phase, even under the proper forming conditions. In order to understand these phenomena, in this paper, phase transformation in a boron steel 22MnB5 under various cooling rates were investigated and the effects of pre-strain conditions on the phase transformations were characterised. Uniaxial tensile specimens were stretched under isothermal conditions to different strain levels of 0-0.3, at strain rates of 0.1-5.0/s and deformation temperatures of 650-800°C. A dilatometer was used to measure the dimensional changes of the specimen to rationalize the phase transformation of the boron steel during rapid cooling after deformation. The results showed that the deformation at austenite phase causes the reduction in martensitic phase transformation. For a certain strain level, deformation applied at a lower temperature and a higher strain rate would result in less amount of martensitic phase transformation. In addition, the relations between hot stamping conditions and Vickers hardness, which are normally used as a daily quality check in the industry, are also presented in the paper.

Matsumoto, Takeki, Li, Nan, Shi, Xin, Lin, Jianguo

Surface Generation speeds composites throughput with one-shot stamp-forming process

16AUTP02_072/1/2016

Surface Generation is working with research group WMG, an academic department of the University of Warwick, and AGC AeroComposites to develop new composite press-forming processes for automotive and aerospace manufacturers. Surface Generation, a U.K.-based provider of advanced carbon-fiber processing technologies, is developing new press-forming mold faces that incorporate its patented PtFS (Production to Functional Specifications) technology for the production of high-performance thermoplastic composite components. By integrating Surface Generation's active thermal management technologies into the mold face itself, WMG and AGC are able to continuously adapt heating and cooling levels for each mold area and process stage in real time. The companies believe that this enhanced capability will improve both the quality and throughput of compression molding applications.

Gehm, Ryan

Surface Generation speeds composites throughput with one-shot stamp-forming process

16OFHP02_062/1/2016

Gehm, Ryan

Automation System Retrofit Transforms 175-Ton Hydraulic Forming Press

TBMG-239472/1/2016

Southern Manufacturing Group (SMG) of Morrison, TN, makes automotive components and industrial valves. In 2012, the automation system for its 175-ton hydraulic forming press received electrical damage resulting from a lightning strike (Figure 1). Purchasing a new hydraulic forming press would be prohibitively expensive — in the range of hundreds of thousands of dollars. Therefore, SMG needed a company that could repair the forming press in a short timeframe to maintain its production schedule.

AS2512 Stamping for Arm (Filler Cap)

AS2512-3 (Current)12/4/2015

No scope available.

Engine and Airframe Technical Standards Committee (TSC)

Methods for Determining Plastic Deformation in Sheet Metal Stampings

J863_201504 (Current)4/28/2015

Metals Technical Committee

Design For Six Sigma (DFSS) for Optimization of Stamping Simulation Parameters to Improve Springback Prediction

2015-01-05824/14/2015

Springback prediction for stamped components is a challenging task for Automotive Industry. Automotive Manufacturers are working to reduce the springback effect of sheet metal stampings caused due to elastic behavior of materials with the help of changes to manufacturing process and part geometry. Recent development in Finite Element Analysis (FEA) studies made it possible for the industry to rely on stamping simulation. There is always a gap between the springback predicted from stamping simulation and the actual stamped part. Currently FEA techniques are trying to close this gap. The objective of this study is to minimize this gap using DFSS method for predicting the springback and optimizing the simulation parameters with the help of LS-Dyna FEM tool. The behavior of material with different simulation parameters has been studied in this paper and the ones that best correlate with actual data are identified. The amount of springback is virtually measured for the stamped part with and without clamping on checking fixture. The results of the baseline simulation before and after optimization are discussed in this paper.

Bhuyan, Deepak Ranjan, Netapalli, Sreekanth, Dev, Sathya, Srinivasan, Soundarya

Innovative Door Design for Commercial Vehicles

2014-01-24119/30/2014

Design of body structures for commercial vehicles differs significantly from automotive due to government, design and usage requirements. Specifically, heavy truck doors are not required to meet side impact requirements due to their height off the ground as compared to automobiles. However, heavy truck doors are subjected to higher loads, longer life, and cannot experience permanent deformation from overload events. Aluminum has been used intensively in commercial vehicle doors and cab structures for over 50 years by several different manufacturers in North America. It has been only in the last few years that aluminum has appeared in automotive door structures other than in high-end luxury vehicles. Commercial vehicle customers are expecting the same features found in premium automobiles resulting in opportunities to learn from each other's designs. In order to optimize the strength and weight of a commercial vehicle door, a new aluminum intensive structure was developed. The new structure featured a unique architecture that was the first in the industry to use a multi-cavity aluminum extrusion joined to stamped sheet reinforcements in order to provide a direct load path between the hinges and the latch. The shape of the extrusion also allows the use of a one piece glass and door mounted mirror. The “barn door” architecture of the inner structure of the door allowed for gauge optimization of the both the inner and outer stampings, the two largest and heaviest components of the assembly. Additionally, the use of an extrusion allowed for a single drop glass for improved visibility and the ability to use a door mounted mirror with only one extra reinforcement. Overall the design architecture used in the new doors provide best in class structural performance, sealing and features normally found in luxury automobiles for the first time in the heavy truck industry.

Auger, Marc, Plourde, Larry, Trumbore, Melissa, Manuel, Terry

The Influence of Vacuum Booster Design Parameters on Brake Pedal Feel

2014-01-24999/28/2014

Brake pedal feel characteristic is determined by the structural and kinetic parameters of the components of the brake system. As the servo power component of the brake system, vacuum booster has a significant influence on the brake pedal feel. In this paper, a brake system model for brake pedal feel which has a detail vacuum booster mathematical description is established in the software MATLAB/Simulink. The structure gaps, spring preload, friction force and reaction disc characteristics of vacuum booster are considered in this model. A brake pedal feel bench test under different input velocity and vacuum pressure is completed in order to validate the prediction of the model. Finally, based on the assessment index in pedal travel, pedal force and master cylinder pressure three-quadrant diagram, the influence of vacuum booster design parameters such as structure gaps, spring preloads, press plate and press ring areas, diaphragm effective area and reaction disc stiffness on the brake pedal feel characteristics is analyzed and discussed. This study can serve as important reference for vacuum booster design and adjustment.

Zhang, Lijun, Ruan, Cheng, Meng, Dejian

Redundant Sensors Improve Precision and Reliability

TBMG-201908/1/2014

Some machine processes, such as presses, can require extreme accuracy in applying and holding force on an object. A popular way to measure force is via load cells. But what do you do when the accuracy required by a particular application is higher than that guaranteed by the load cell manufacturer?

Development of Thermoplastic Composite Cones for Helicopter Tail Boom Application

F-0070-2014-9560

5/20/2014

Thermoplastic composites offer many attractive characteristics such as no shelf life, high fracture toughness, high temperature resistance, recyclability etc. The short coming of thermoplastic composites is their high viscosity, even at processing temperature. Due to the high viscosity, techniques for the manufacturing of thermoplastic composite have been limited to molding processes such as compression molding, high temperature stamping, where high temperature, high pressure and long duration are used. The advent of automated fiber placement machine brings forward possibilities to manufacture of large thermoplastic composite components. This is due to the fact that heating and compaction is done on the go directly on the surface of the substrate, and the flexibility of the feeding head to conform to the shape of the mold. It is in the spirit of exploration for new manufacturing possibilities that Bell Helicopter has supported an inter industry- university project for the development of thermoplastic composite cones aimed at helicopter tail boom applications. The cone represents a segment of the helicopter tail boom. It is made using carbon/PEEK material and automated fiber placement. The work consists of the Determination of the lay-up sequence to address the loads, the Development of the manufacturing processes, the Measurement of temperature variation during the making of a ring, the Checking of the quality of the cone, Development of tube bending test set up, Development of theoretical calculations to determine the buckling load of the cone subjected to bending, Testing the cone under bending load, and Comparing the experimental buckling with calculated buckling load.

Hoa, Suong, Shadmehri, Farjad, Cai, Xiao, Simpson, Jeff, Hojjati, Mehdi, Hubert, Pascal, Quinlan, Erin, Beaulieu, Pierre, Dion, Michel

Application of Structure Optimization Method to Dynamic Tuning

2014-01-04114/1/2014

The understeer of vehicle is desired for the vehicle's handling performance, and the roll rate of rear suspension is one of the key characteristics to achieve the understeer performance. A proper roll rate of the rear suspension is required to assure a certain level of understeer. Generally, in the vehicle dynamic tuning process, several methods are available for improving understeer performance, e.g., changing the hard-points of suspensions, adjusting stiffness of bushings, etc. On the other hand, structure optimization of components can be used in some case to improve the performance. In this paper, the optimization method is applied to the twist beam of rear suspension. The change in local geometry by optimized design leads to appropriate adjustment of the roll rate. Finally the vehicle understeer performance reaches design target.

Qu, Yuan, Hongbin, Wang, Zhang, Dechao, Zhang, Linbo, Wu, Shen

Hot Stamping of a B-Pillar Outer from High Strength Aluminum Sheet AA7075

2014-01-09814/1/2014

This work demonstrates the feasibility of hot stamping a B-pillar outer panel from aluminum alloy 7075. AA7075 is characterized by a high strength to weight ratio with yield strengths comparable to those of DP and TRIP advanced high strength steels. Applications using AA7075 have typically been limited to the aerospace industry due to the high variable cost associated with forming and joining of these materials. A primary key to implementation in the automotive industry is the development of metal forming methods that produce non-compromised stamped parts at automotive manufacturing volumes and costs. This work explores the feasibility of die quenching a hot blank within a cold die as a means of delivering high strength aluminum sheet parts. A die made from kirksite was used to evaluate the hot stamping process for a B-pillar outer. After the forming/quenching operation, the parts were subjected to an artificial aging process to regain the properties of the T6-temper. The results show that hot stamping, followed by an adequate artificial aging treatment, produces a high strength component with material properties equivalent to the as-received T6 properties delivered by the material sheet supplier. In addition, the hot stamped B-pillar component demonstrated limited springback with a high level of dimensional accuracy.

Harrison, Nia R., Luckey, S. George

Integrated CAE Methods for Perceived Quality Assurance of Vehicle Outer Panels

2014-01-03664/1/2014

Oil canning and initial stiffness of the automotive roofs and panels are considered to be sensitive customer ‘perceived quality’ issues. In an effort to develop more accurate objective requirements, respective simulation methods are continuously being developed throughout automotive industries. This paper discusses a latest development on oil canning predictions using LS-DYNA® Implicit, including BNDOUT request, MORTAR contact option and with the stamping process involved, which resulted in excellent correlations especially when it comes to measurements at immediate locations to the feature lines of the vehicle outer panels. Furthermore, in pursuit of light-weighting vehicles with thinner roofs, a new CAE method was recently developed to simulate severe noise conditions exhibited on some of developmental properties while going through a car wash. This paper introduces such a method to discuss Fluid Structure Interaction (FSI) approach using an Arbitrary Lagrangian Eulerian (ALE) formulation in LS-DYNA® for vehicle roof car wash boom noise prediction. This CAE method was developed to simulate force behavior from airflow as the car wash air blowers are expelling high speed air at the vehicle roofs during car wash. LS-DYNA® was proven an appropriate tool to precisely simulate popping noises by creating instantaneous local instabilities - recoverable/non-recoverable - and continuous fluttering of the roof. This paper additionally briefs the history of oil canning CAE method developments from inaccurate hand push evaluation to approaches using MSC Nastran® to Abaqus/Standard®, and then the final evolution to LS-DYNA® Implicit to provide optimized vehicle solutions.

Jang, Jaehyuk

Experimental Evaluation of the Quench Rate of AA7075

2014-01-09844/1/2014

The aluminum alloy 7075-T6 has the potential to be used for structural automotive body components as an alternative to boron steel. Although this alloy shows poor formability at room temperature, it has been demonstrated that hot stamping is a feasible sheet metal process that can be used to overcome the forming issues. Hot stamping is an elevated temperature forming operation in which a hot blank is formed and quenched within a stamping die. Attaining a high quench rate is a critical step of the hot stamping process and corresponds to maximum strength and corrosion resistance. This work looks at measuring the quench rate of AA7075-T6 by way of three different approaches: water, a water-cooled plate, and a bead die. The water-cooled plate and the bead die are laboratory-scale experimental setups designed to replicate the hot stamping/die quenching process. The results verify that water is the most superior form of quenching, i.e. above 1000°C/s, the bead die quench rate is impressive at 525°C/s, and the water-cooled plate quench rate is marginal at 34°C/s. Consequently, the results also indicate a strong correlation between quench rate and final yield strength properties.

Keci, Aledoni, Harrison, Nia R., Luckey, S. George

On Modeling the Hot Stamping of High Strength Aluminum Sheet

2014-01-09834/1/2014

This paper documents the finite element (FE) analysis of a hot stamping process for high strength aluminum sheet. In this process a 7075 blank, heated above its solvus temperature, was simultaneously die quenched and stamped in a room temperature die to form a B-pillar outer reinforcement. Two modeling approaches have been investigated: an isothermal mechanical model and a non-isothermal coupled thermo-mechanical model. The accuracy of each approach was assessed by comparing the predicted strain and thickness distributions to experimental measurements from a formed panel. The coupled thermo-mechanical model provided the most accurate prediction.

Ilinich, Andrey, Luckey, S. George

A Fastener Analysis Addressing Various Types of Misfit and Its Damage Life Calculations

2013-01-23129/17/2013

In a fastening system when there is a small misalignment of the holes, the holes are enlarged to align the axes and a next size fastener is used to fit the joint. But when the misalignment is large then the enlargement need to be proportionally large. In this case a bushing is press fit onto the hole to handle the fastening. If we press fit a bushing, it generates residual stresses in the panel. These residual stresses reduce the damage life of the components on which the bushings were press fit. In the aircraft engine nacelle components the damage life is very critical in various failure conditions such as fan blade out condition, wind milling and bird strike. It increases the flight time in these events. Here four different case studies were considered to study the damage life of the aircraft components made of Aluminum or composite material. Case-study 1 (Aluminum panel and full ring bushing): A knock down factor to the damage life for the component material (Aluminum - in this case) is tabulated in this paper to account for the pre stresses added to the nacelle components due to the press fit of the bushing, which is added due to the misalignment of the holes. Case-study II (Aluminum panel and split ring bushing): An attempt is made to reduce the residual stresses on the Aluminum panel containing the fastening system for the non critical components. Here a split ring is used to press fit into the enlarged hole [1] in place of the bushing used in the Case-study I. The split ring reduces the tolerance requirements and decreases the manufacturing cost & time. This also reduces the stress on the panel and contains the fastening system. Case-study III (Composite panel and full ring): In this case- study the bushing is press fit into composite sandwich panel instead of the Aluminum panel that is used in previous Case-studies for a treatment on the misalignment. The residual stresses developed are used to recalculate the damage life of the composite panel. Also a knock down factor chart is developed for the fiber with +45. −45, 0 and 90 degree ply orientations. Case-study IV (Composite panel and split ring): In this case-study the split ring is used instead of full ring bushing on to the composite panel. These studies can be used to modify the damage number for the given material of any part subjected to a peak pre stresses between 4 to 12 Ksi. By computing the modified damage number, the RUL (Rest of Useful life) number can be computed. This helps in accessing the health of the part as well as can decide in reusing a part in non critical system as a carry over part. The split ring bushing is studied only to be used in the non-critical parts or in other systems such as automotive or consumer industrial components. For the critical aircraft components the added residual stresses will necessitate to compute the modified margin of safety as well as the modified damage life for the part.

Anandan, Vailore

Test Slabs, Acrylonitrile Butadiene (NBR-H) Medium-High Acrylonitrile, 65 - 75

AMS3217/1B (Historical)9/16/2013

This specification covers a standard acrylonitrile butadiene (NBR-H) rubber stock with medium-high acrylonitrile content in the form of molded test slabs.

AMS CE Elastomers Committee

Synthetic Resin Plastic Sealers, Nondrying Type

J250_201307 (Current)7/9/2013

The material desired under this recommended practice is a synthetic resin plastic sealer of the nondrying, nonbleeding, and noncorrosive type that may be extruded to the specified size and used as a medium for producing a water tight seal between 2 pressed steel sections or between rubber and steel.

Materials, Processes and Parts Council

Integrating Manufacturing Pre-Stress in FEA Based Road Load Fatigue Analysis

2013-01-12044/8/2013

Most manufacturing and assembly processes like stamping, clamping, interference fits introduce a pre-stress condition in components or assemblies. Very often these stresses are high enough and alter the mean stress state resulting in significant effect on fatigue life performance and thus cannot be ignored. If the pre-stress is compressive, it will increase the allowable stress range and improve fatigue life performance; on the other hand if these stresses are tensile, they will decrease the allowable stress range resulting in a degradation of fatigue life. At times it becomes critical to effectively introduce the pre-stress condition in order to accurately represent the stress state in an FEA based durability simulation. Accounting for the pre-stress state in FEA based constant amplitude loading fatigue life simulation is relatively straight forward, but when it comes to random variable amplitude multi-channel loads simulation, the problem becomes more complicated. In this paper, a method to include the pre-stress effect on vehicle components or assemblies and perform FEA based fatigue analysis when subjected to random road loads is practiced. This paper outlines the procedure used to calculate the pre-stress followed by the modified material curves and eventually performs FE based fatigue analysis using vehicle road load data. A couple of case studies are also included that will demonstrate the correlation of this FE based method to the physical component test results.

Qin, Wenxin

Die Wear Estimation in Automotive Sheet Metal Stamping

2013-01-11714/8/2013

Automotive industry's migration to usage of HSS (High Strength Steels), AHSS (Advance High Strength Steels) from conventional steels for their low weight and high strength properties has had its significant effects on die wear. The unpredictability of die wear can pose manufacturing issues, for example, undesirable tool life. Hence die wear has been gaining immense attention and lot of research work has been carried out to provide a die wear prediction method. This paper focuses on the method of estimating wear mathematically based on the mechanics behind die wear phenomenon. This is also an effort to study wear on die for an automotive component in critical areas for which the amount of wear are calculated. This study is further to be correlated with production data from die maintenance record, explicit measurement of die wear, etc., to validate the estimation.

Balakrishnan, Praveen Balaj, Dev, Sathya, Bhuyan, Deepak, Syed, Parvez, Thokala, Sarin Babu

Time Manager Software for a Flight Processor

TBMG-1486710/1/2012

Data analysis is a process of inspecting, cleaning, transforming, and modeling data to highlight useful information and suggest conclusions. Accurate timestamps and a timeline of vehicle events are needed to analyze flight data. When data is gathered onboard a rocket, precise time stamping is even more important due to the rocket’s high speeds and the requirement to integrate data over time for inertial navigation calculations.

Analytical Method to Determine Press-fit Tolerance between Torque Carrying Members

2012-01-19969/24/2012

This paper deals with an analytical method to calculate the press-fit tolerance and fits between gears and shaft for automotive applications. The relative interferences increase sharply in the small diameter range, therefore one must be especially careful when designing small diameter joints. The strength of press-fit depends on the amount of relative interference; extreme interference leads to excessive contact stresses between the gear and shaft eventually leading to failure. Too little interference leads to slippage of gear on the shaft. In the press fit connection a shaft's spline rolling operation and gear internal broaching is eliminated. It is more economical than a conventional spline connection. Press fit connections are used in various transmission between a shaft and a gear. They are used in 6 speed transmission to 9-speed transmission for (German based Vehicle Manufacturer) heavy and light commercial vehicle company. In India 5-speed transmission to 9-speed transmission for heavy and light commercial vehicle companies, also uses press fit connections. The strength of the press fit joint is directly proportional to the coefficient of the friction between the mating parts. The strength depends upon the pressure at the contacting surface, surface micro irregularities and material properties. Adequate surface finish of the mating component is an essential condition for the strength of the pressed connection. For connections undergoing heating during the operation, the influence of the temperature upon the fit must be considered. Therefore it is challenge to design an optimum press fit joint; a fine balance need to be determined while calculating interferences for the press-fit connection.

Bhat, Muralidhar Suryanarayan, Jadhav, Sagar

High-Accuracy Closed Loop Force Feedback

TBMG-140867/1/2012

Hand-driven press assemblies, which require a specific amount of force applied for a given amount of time, present challenges when attempting to accurately measure or replicate results in production or quality control processes. In contrast, servo-driven digital presses are able to provide accurate, consistent, and repeatable results while outputting trackable data. By controlling position and current, the servo-driven digital press allows for stable, accurate, and repeatable control.

Test Slabs, Acrylonitrile Butadiene (NBR-L) Low Acrylonitrile, 65 - 75

AMS3217/2C (Historical)4/27/2012

This specification covers a standard acrylonitrile butadiene (NBR-L) rubber stock with low acrylonitrile content in the form of molded test slabs.

AMS CE Elastomers Committee

Advantages of Manufacturing Silicone Drug-Eluting Components via Ultraviolet Light Vulcanization Process

TBMG-128172/1/2012

Combination products offer several advantages when compared with drug delivery via oral, injection, and infusion methods. All drug-device type combination products exhibit one or more of the following attributes. First, they provide controlled release of the active pharmaceutical ingredients (API) instead of bolus-type delivery; API concentrations can be consistently maintained within an optimal therapeutic range. Second, drug-eluting devices, particularly implanted devices, allow for a targeted delivery of the API. This targeted approach, when contrasted with systemic administration, permits higher therapeutic dosages to be delivered while minimizing adverse side effects. Third, combination products have been shown to improve patient compliance. Most healthcare practitioners now agree that within our aging population, compliance becomes less certain and therefore more important.

Beryllium Bars, Rods, Tubing, and Shapes, Optical Grade

AMS7905C (Current)12/2/2010

This specification covers beryllium in the form of bars, rods, tubing, and machined shapes fabricated from vacuum hot pressed powder.

AMS G Titanium and Refractory Metals Committee

Aluminum Alloy Extrusions, 1.0Mg - 0.60Si - 0.28Cu - 0.20Cr (6061-T5511), Press Heat Treated, Stress Relieved by Stretching, Straightened, and Artificially Aged

AMS4294A (Current)12/2/2010

This specification covers an aluminum alloy in the form of extruded bars and rods.

AMS D Nonferrous Alloys Committee

Dynamic Testing of Electromechanical Actuators Using Time-history Data

2010-01-174811/2/2010

A commercial electromechanical actuator (EMA) is to be dynamically tested with predetermined stroke and load profiles for transient thermal and electric power behavior to validate a numerical model used for aerospace applications. The EMA will follow the stroke profile representative of a real aircraft mission duty cycle. A hydraulic press will exert a corresponding load profile onto the EMA. Specialized hydraulic load control methods must be employed to meet the accuracy requirements. Two of these methods are closed-loop linearization (CLL) and displacement induced disturbance cancellation (DIDC). These methods are implemented along with an external PID compensator, and run in real-time in a series of system identification experiments to observe controller performance.

Rolinski, Nicholas E., Leland, Quinn, Gregory, Earl, Jordan, Brett, Woodburn, David, Wu, Thomas

Fiberboard Crease Bending Test

J119_201005 (Historical)

5/10/2010

This test method is designed to determine the suitability of a painted or unpainted fiberboard for application involving creasing and bending. The specific purpose of the test is to determine whether a given material, properly creased, can be bent along the impressed crease without objectionable failure on the surface of the bend.

Textile and Flexible Plastics Committee