Effect of impulse loading on cracked beam with L-shaped cross section

Abstract

This paper deals with the determination of the dynamic stress intensity factor (DSIF) for two locations of a crack in the beam with L-shaped cross section. The cracks pass through the entire profile body thickness in both position cases.The results shown below were obtained by 3D finite element analysis. Considering only static load (axial tensile) on a beam under given boundary conditions, the SIF for modes II and III was negligible compared to the SIF for mode I. In the case of impulse loading, the mixed mode of loading was introduced due to reflective stress waves.In the first step of analysis, the static SIF was determined for given cracked body geometries. Subsequently, the natural frequencies and their respective ratio of effective to total mass were calculated by modal analysis. After identifying the dominant natural frequency at which the beam oscillates in the direction of the longitudinal axis was done, the duration of time step required for transient analysis was determined.The analysis results are the time record of the SIF for all three loading modes of crack. The results of tensile and compressive impulse forces in the form of half-wave function sine are compared. Overall, six cases are evaluated depending on the position of the crack and the applied external load.This paper deals with the determination of the dynamic stress intensity factor (DSIF) for two locations of a crack in the beam with L-shaped cross section. The cracks pass through the entire profile body thickness in both position cases.The results shown below were obtained by 3D finite element analysis. Considering only static load (axial tensile) on a beam under given boundary conditions, the SIF for modes II and III was negligible compared to the SIF for mode I. In the case of impulse loading, the mixed mode of loading was introduced due to reflective stress waves.In the first step of analysis, the static SIF was determined for given cracked body geometries. Subsequently, the natural frequencies and their respective ratio of effective to total mass were calculated by modal analysis. After identifying the dominant natural frequency at which the beam oscillates in the direction of the longitudinal axis was done, the duration of time step required for transient analysis was determined.The analysis results...