Foam Modelling for Child Restraint Systems

Sammanfattning: Computer simulation is an essential tool in the development process of childseats, particularly when it comes to ensuring the safety of child passengers.As awareness regarding child passenger safety continues to grow, the use ofsuitable materials in the development of child seats becomes increasinglycrucial. Numerical simulations play a vital role throughout the entiredevelopment phase, enabling accurate analysis and evaluation. Toeffectively reduce development costs and time, it is imperative to have amaterial model that accurately predicts the behavior of materials innumerical simulations. This enables optimized performance of child seatswhile maintaining safety standards. The objective of the thesis is to implement a standard procedure forextracting material data for numerical modelling of foam materials andvalidating it. In this study, material models available in LS-DYNA, such asMAT_083 and MAT_057 for foam materials, are utilized along withcompression test data to create the material model. The model is furtherenhanced by optimizing the material parameters to establish a correlationbetween the test and simulation results. The improved material model is thenvalidated by comparing it with the impact drop test results. However,THULE's current impact drop test equipment is not considered accurate orefficient, and addressing this issue is one of the main objectives of thisthesis. Within this thesis, the identified problems are thoroughly examined,and suitable solutions are proposed to ensure the accurate extraction ofmaterial data and its validation, particularly when introducing new foammaterials.