An Approach for Modeling Shock Propagation Through a Bolted Joint Structure

Impact loading is typically characterized by a relatively large load happening over an extremely short duration and inducing broad range of vibration frequencies. Standard design approaches of bolted joints based on static or quasi-static criteria may not be effective under these conditions. This study focused on simulating a drop-weight tower experiment where a free-falling mass impacted a target plate, which was bolted to a cylindrical structure. An accelerometer was used to record transmitted acceleration to the cylindrical structure. An approach for simulating the shock propagation was proposed using LS-DYNA® Explicit finite element code. To reduce computational time, thread was not included. Instead, bolts were represented as cylinders with cross-sectional areas equal to the tensile stress area of the bolts. The results showed good agreement between the finite element and experimental results.