Ultimate Breakage Load Calculation Method of Cold Gas Inflator Burst Disk
2022-01-0938
03/29/2022
- Event
- Content
- For cold gas Inflator, high refinement of ultimate load forecast is one key of Inflator development. At beginning, two methods based on implicit algorithm, Zero Curvature method and RIKS method were used for burst disk hydro-burst test ultimate pressure load calculation. After considering the effect of bursting disk stamping process, comparing with results of real test, the refinement of the two methods were above 97% both. Studying the corresponding relations between displacement and stress matrix of the center point of burst disk by RISK method. It was found that under ultimate load, the third principal stress vs. displacement curve of the central node shown extreme point, and load step of the point was corresponding the one of maximum pressure load. This shown that after reaching the ultimate load, the center of the bursting disc lost stability in the direction of thickness. Based on the status of stress matrix analysis results of RIKS method, and for solving the nonlinear contact convergence issue of implicit algorithm, explicit algorithm was used to solve ultimate load. The method of stress matrix status analysis was put forward to judge ultimate load of explicit algorithm results. The load coincides with burst disk center position just became plastic instability in thickness direction will be defined as ultimate load. This method not only take the advantage of explicit algorithm in solving contact nonlinearity and easy convergence, but also avoids the discrepancy caused by incomplete force balance of explicit algorithm in case of local structure instability. Finally, the refinement of ultimate load is 97.4% contrast to real test judging by the method of stress matrix status analysis calculated by explicit algorithm. Furthermore, by involving the effect of nonlinear contact, the refinement of displacement of burst disk is better than implicit algorithm.
- Citation
- Shan, J., and Wang, C., "Ultimate Breakage Load Calculation Method of Cold Gas Inflator Burst Disk," SAE Technical Paper 2022-01-0938, 2022, .