Influence of strain rate effect on dynamic bending strength of concrete

The relationship between strain rate and dynamic strength as well as the relationship between strain rate and elastic modulus are deduced based on the experimental data. The finite element numerical model for describing the dynamic loading process of concrete beam is established according to the relationships between the strength, elastic modulus and strain rate. By using this model the dynamic bending failure process of beams under the action of shock loading with various strain rates and various static preloading levels are simulated. The strain-rate sensitivities to concrete dynamic strength and elastic modulus for various preloading levels are analyzed and the relationship between dynamic strength and strain-rate is deduced. It is found that the dynamic strength of concrete is dependent upon the strain history, strain rate history and damage accumulated in the process of loading.