The need for the protection of workers in many industrial workstations has long been recognized, and many types of protective equipment have been devised. In many protective equipment designs, this study set limits to the safety helmet.
The direct closed head impact problem was idealized as a linear-damped spring model. The study concerns what material of helmet should afford optimal protection in a direct closed head impact problem.
The solution to the problem was achieved through analytic method and numerical computation. The answer was found in terms of 4 parameters : 1) rigidity of shell, 2) viscosity of shell, 3)rigidity of harness, 4) viscosity of harness.
The optimal choices are as follows 1) to reduce the rigidity value of harness as small as possible 2) to increase the viscosity value of harness as large as possible. 3) to select the rigidity value of shell sufficient for preventing the breakage.
