Residual Effects of Metal Forming on Seat Belt Pull Analysis Results

Automotive industries are emphasizing more and more on occupant safety these days, due to an increase in awareness and demand to achieve high safety standards. They are dependent on simulation tools to predict the performance of subsystems more accurately. The challenges being encountered are designs which are getting more complex and limitations in incorporating all real-life scenarios, such as to include all manufacturing considerations like forming and welding effects. Latest versions of solvers are slowly introducing new options to include these actual scenarios. Ls-Dyna is one of the explicit solvers to introduce these possibilities. The process of including stamping details into crash simulation is already being performed in the automotive industry. However, for seatbelt pull analysis, this has not been explored much. Incorporating stamping effects could be one step further in improving the accuracy of Seatbelt pull analysis and closer to real life test conditions if fully investigated. Stamping alters the material properties and thickness of the body parts while undergoing the forming process during manufacturing, but this effect is generally not considered in simulations. This change might improve or degrade the design of body structure in terms of strength. So the overall effect of incorporating stamping details in the seatbelt pull virtual assessment is still not known, since material properties are enhanced due to effect of strain hardening and thinning of component takes place as well. This paper shall discuss the effect of Stamping on BIP (Body in prime) structure, for assessment of Seatbelt pull analysis, as per FMVSS225 207/210 Regulation. Critical parts in body structure were filtered and different test cases were run, including and excluding stamping details for these parts. Quasi-static simulation was performed and results for three different test cases were analyzed. Overall effect is studied through final results in terms of graphs and tables in this paper.