Finite element modelling and validation of the honeycombs for automobile crash MDB and ODB

Honeycomb materials are widely used in automotive crash tests. Typically, it is the main components of the ODB (Offset Deformable Barrier) and MDB (Mobile Deformable Barrier) stipulated in ECE Regulation No.94 and No.95 on automotive crash test. These two kinds of honeycombs or barriers are also adopted by Chinese regulations. The accuracy and efficiency are most important for the CAE analysis of automotive crash simulation. In the earlier the solid elements is mainly employed for honeycomb modelling due to the limitation of computer calculation. The challenge of the solid element modelling is to overcome the hourglass energy, computational stability and local deformation simulation, etc. Recently, with the rapid improvement in computer hardwires, the shell elements are [1][2][3] more and more used for modelling the honeycomb . The shell model for honeycomb has some advantages such as high computational stability, lower hourglass energy and good simulation for detailed local deformation. The shell models of honeycomb can be found from the LSTC Inc. and [3] Wang . In China, the majorities of auto manufacturers still use the solid model of honeycomb from overseas commercial models such as ARUP and ESI honeycomb models. The shell model of honeycomb hasn’t yet been widely used because it is in grow-up stage and needs more validations for its accuracy. Meanwhile, some data or parameters in these commercial models is invisible and cannot be handled. Furthermore, some problems were found in the actual CAE applications, such as too strong glue, excessively hard character of the whole honeycomb and abnormal energy, and so on. On the other hand, many auto manufacturers still insist on developing own honeycomb models so that they can grasp the whole analysis simulation. Based on the experimental data and other literatures, this paper presents the FE models of ECE ODB and MDB developed by LS-DYNA®. By means of whole vehicle crash validations, these two models can give a good accuracy and computation stability. All the codes of these models will be opened to the public so that it will be helpful for auto engineers to comprehend the details of the honeycomb model and to improve the models.