Composite material properties can change with the rate at which load is applied. For shock, vibration or impact analysis it is important to understand the changes in mechanical properties in either the time or frequency domain in order to have a reliable prediction.
Damping characteristics of composites change with frequency and can dramatically affect the outcome of a prediction as the internal forces in the structure are either amplified or attenuated as the simulation progresses.
In crash, composite materials are highly rate dependent, characterised by a low speed transition from a higher quasi-static level into a significantly lower value which typically stabilises in the range 0.5 to 2.0 m/s. The ratio between the levels is related to the type and constituents of the composite.
Properties Affected by strain rate;
Engenuity have developed close relationships with testing specialists and understand the requirements of dynamic testing to be able to specify the properties in the analysis domain.