Experimental investigation and numerical simulation of the crash behavior of composite materials
The design of advanced composite front structures for motor vehicles demands a detailed knowledge of the crash behavior and energy absorption during a collision. Thin-wall metallic structures subjected to crash load fail by buckling and folding, whereby the energy is mainly absorbed by plastic deformation. The crash behavior of fiber reinforced plastic structures is affected by the properties of the fiber and the matrix, the volume fraction of the fiber, the orientation of the fibers, the stacking sequence of the layers, the geometry of the structure and the force triggering system. The energy is absorbed by multiple fractures of fibers, matrix and interface, fiber pullout and delamination of the layers. Within the scope of the research work fundamental studies on the crashworthiness and energy absorption characteristics of glass fiber-reinforced vinyl and polyester resins were conducted. They were performed on specimens with simple geometry like tubes and cones. The specimens were manufactured by filament winding and hand lay-up. For the crash tests two test rigs were developed and set up. A description is given of the design, the instruments for recording, the measured data, and the evaluation of the experiments.
The study of the crash behavior of composite materials embraced the effect of various systems for applying the impact force (triggering), the geometry of the specimen, the make-up of the laminate and the fiber orientation. It was demonstrated, that the advanced composite tubes absorbed much more energy per unit weight than the aluminum cylinders that were also tested to provide a comparison.
In a second step numerical simulations of the crash behavior of advanced composites were performed. Material models for composite shell and solid elements were developed and implemented in the DYNA3D finite element program. The crash behavior of thin-wall aluminum tubes was also analyzed mathematically to verify the results of the experiments and simulations. Tubes with cylindrical and square cross section were taken as an example to check and validate the developed material models for the numerical crash simulation of composite structures. Comparing the numerical and experimental results, a fairly good agreement was found for the global crash parameters. In order to gain better results, material data from dynamic tests should be taken for input data. Delamination plays an important role in energy consumption of composite structures and should be considered in an improved analysis with shell elements.Lesen Sie die deutsche Zusammenfassung auf Kunststoffe.de
composite material, energy absorption, crash simulation, material model, crash test
Institute / chair: Fachbereich Maschinenwesen der Universität Kaiserslautern
Technical consultant for expert services: Prof. Dr.-Ing. M. Neitzel (Betreuer), Prof. Dr.-Ing. W. Steinhilper, Prof. Dr.-Ing. A. Weber
Publication year: 1990
Provider: Wissenschaftlicher Arbeitskreis Kunststofftechnik (WAK) / Kunststoffe.de
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