In this case study, we provide a detailed demonstration of the process of developing a material card for polypropylene (PP) used in vehicle bumper systems. From initial laboratory testing to final validation through crash simulation.
Initial situation and project objectives
The development team of our client was working on the design of a plastic bumper made of PP and encountered the limitations of commonly available library data. The material card in use did not correspond to the actual material formulation, completely neglected impact loading, and showed significant discrepancies between simulation and physical testing.
The main objective of the project was therefore to obtain a realistic and validated material card for the Abaqus and Pam-Crash environments, ensuring safety and accuracy in future impact simulations.
Material and Application
The application to a passenger vehicle bumper placed high demands on the accuracy of the material model, as the component had to effectively combine energy absorption, toughness, and dimensional stability. For these purposes, it was necessary to capture not only quasi-static and dynamic loading, but also the temperature-dependent behaviour of the material.
Material Testing as the Basis for Simulation
Mechanical testing in line with automotive practice formed the basis for describing the real behaviour of PP. We conducted tensile tests at various strain rates, impact tests, and detailed evaluation of plastic deformation and failure at relevant temperatures. The measured data were subsequently processed with high precision for the purposes of numerical modelling.
Development of the FEM Material Card
Based on these experimental outputs, we selected the optimal material model and identified key elastic and plastic parameters. The development process included defining material failure criteria and optimising parameters specifically for impact loading. The resulting material card was fully prepared for integration into the Abaqus and Pam-Crash solvers.
Numerical Validation
The accuracy of the developed material card was verified using FEM simulations of laboratory tests, where we focused on comparing force–displacement curves and the energy absorbed during impact. Very good agreement with the experimental results confirmed the model’s ability to correctly predict both the location and the mode of failure.
Component Simulation
The validated material card was subsequently used in the simulation of a real bumper, enabling the observation of realistic component deformation and stress distribution. Thanks to this reliable prediction of energy absorption, the client was able to identify critical areas of the design and optimise the component before the production of physical prototypes. This approach leads to higher accuracy of crash simulations, a reduction in the number of physical tests, and an overall shortening of the development cycle. The client gained confidence in design decisions and obtained a material card ready for further projects.
Why Partner with LENAM
Our added value lies in the unique combination of experimentation and simulation. We have a deep understanding of the behaviour of thermoplastics in the automotive environment. We deliver validated, industry-ready material cards that provide confidence. If you require your simulations to truly reflect reality, we will help you get the most out of FEM simulations.
Are you facing a similar challenge and need greater confidence? Are you considering simulations before physical testing? Schedule a short technical consultation with our expert. Together, you will discuss the specifics of your project and identify potential weaknesses in your existing models.
LENAM s.r.o. is a specialised engineering company focused on the development and validation of FEM material cards for automotive applications. We help manufacturers and development teams achieve reliable and predictive simulations that accurately reflect the real behaviour of plastic components.