Finite Element Modeling and Analysis of Crash Safe Composite Lighting Columns, Contact-Impact Problem

Three Finnish associates, Tehomet Ltd, Fibrocom Ltd and Mikkeli Polytechnic Research Center YTI developed an internationally awarded energy absorbing lighting column product family in 2005. The design and dimensioning were assisted with static FEM computations, preliminary impact tests and full-scale impact tests made by YTI. The CompMechLab helped these associates in product optimization and further development by developing lighting column FE-models with sufficient energy absorbing properties, by fitting the model to obtain similar deceleration curves with real car crash tests, and to provide recommendations concerning the design of new, higher columns. Developed fully 3-D CAD and FE models of different column types featured the simulation of the following nonlinearities: dynamic impact at different vehicle speeds, plasticity in column and vehicle parts, contact interaction between the simulated objects and progressive damage in column laminates. 3-D FE model of the impact car was based on FHWA/NHTSA National Crash Analysis Center prototype including radiator, engine, front and rear suspensions, brake system and many other parts with ability of contact interaction and nonlinearities in material behavior. Prototype design was modified to get approximate similarity with the Peugeot 205 car used in the experiments. Column 3-D FE model includes column stand, reinforced composite laminates and bracket with lanterns (single or double). Al together 216 different materials were used in the FE- model of the car and the lighting column. The resulting simulated deceleration curves allowed calculating Head Injury Criteria – conforming Federal Motor Vehicle Safety Standard – and estimating safety reliability for all columns crush tests. Computed Head Injury Criteria values combined with maximal deceleration values proposed the constructions to be safe ones.