抄録
A method of reducing the concentration of dynamic stress, which utilizes the interference effect of the stress wave, was investigated. Impact compression load is applied to a strip specimen with circular cut-outs made of polymethylmethacrylate. These cut-outs consist of a central cut-out and two additional cut-outs with varied diameter, d, and distance between the cut-outs, pitch p, on the strip. Dynamic elastic stresses on the minimum section of the cut-outs are calculated using the DYNA3D software, and the stress concentration factor K was also obtained. The K at the central cut-out decreased as the diameter of the added cut-outs was increased. Because of the interference of the reflected wave and the circumferential propagation of the stress wave around the edges, it is considered that the amplitude of the stress at the edge of the central circular cut-out was reduced. Therefore, this reduction method in which circular cut-outs are added is useful for the impact safety design of mechanical structures. Experiments showed similar results.
