When the driver sits on the seat, the cushion supports more than 70% of body weight. Based on this the driver feels discomfort due to the pain and numbness caused by body pressure concentration in the ischial tuberosity. So, the purpose of this study is to analyze the stiffness of the seat cushion according to sitting strategy and to obtain basic data that can be reflected in the design of the seat cushion pad. First, the static stiffness characteristics of the seat cushion pad were determined through a static load test. Next, we measured the body pressure distribution of 20 subjects. Based on this, we derived 7 types of average body pressure distribution. And as the hardness distribution of the seat cushion, it was judged that it would be less hard feeling at the pressure concentration region. Finally, we compared the deflection and stiffness of the seat cushion using the average body pressure distribution and the static stiffness data of the seat cushion.

A Blast valve is the device that is used in the air intake and the exhaust vent of CBRN(Chemical, Biological, Radiological and Nuclear warfare) protection facility. The valve is automatically closed when explosion pressure is applied from the outside of equipment. This study is investigated on the structural design and the performance of blast valve. After modeling the entire of blast valve and spring assembly, the data for the spring parameter is obtained through the finite element method and the operating limits of the valve are derived. Also, a prototype is made to determine the relationship between the load and the opening closing amount of valve through the load cell test. The performance of prototype at analysis as blast valve is agreed well with that at experiment. It is verified that the blast valve proposed in this paper is designed with the structure to endure the explosion pressure.