Focusing on the lubricant film flow with phase change between the engine piston pin and connecting rod small end, we developed a new multiphase fluid-structure coupled analysis method that takes into account elastic deformation of the structure and flow path changes and developed a simulation prediction method for tribological properties under high load conditions. The simulation prediction method for tribological properties under high load conditions has been created. As a result, we succeeded in simulation prediction of the wear/seizure generating areas in sliding parts. We discovered that the peculiar deformation behavior of the components is the cause of wear/seizure.

It has been thought that computational prediction is impossible to verify the wear and seizure locations in fluid lubrication. Still, this study succeeded in the simulation prediction of wear and seizure locations in sliding parts.

• Numerical prediction of the wear and seizure locations in the sliding parts of engine piston pins was successfully performed.
• The bow-like deformation of the piston pin was identified as the cause of mechanical contact and seizure at the connecting rod edge.
• A three-dimensional multiphase fluid-structure coupled analysis method has been successfully developed, considering the piston pin's elastic deformation and connecting rod and thin-film cavitation1 lubrication with unsteady flow path changes.

This research method applies to automotive engines and all sliding component elements using fluid lubrication. It contributes to damage prediction and the development of safety guidelines for transportation and industrial machinery components, enabling the optimal design of components.

Focusing on the lubricant film flow with phase change between the engine piston pin and connecting rod small end, we developed a new multiphase fluid-structure coupled analysis method that takes into account elastic deformation of the structure and flow path changes and developed a simulation prediction method for tribological properties under high load conditions. The simulation prediction method for tribological properties under high load conditions has been created. As a result, we succeeded in simulation prediction of the wear/seizure generating areas in sliding parts. We discovered that the peculiar deformation behavior of the components is the cause of wear/seizure.

It has been thought that computational prediction is impossible to verify the wear and seizure locations in fluid lubrication. Still, this study succeeded in the simulation prediction of wear and seizure locations in sliding parts.

• Numerical prediction of the wear and seizure locations in the sliding parts of engine piston pins was successfully performed.
• The bow-like deformation of the piston pin was identified as the cause of mechanical contact and seizure at the connecting rod edge.
• A three-dimensional multiphase fluid-structure coupled analysis method has been successfully developed, considering the piston pin's elastic deformation and connecting rod and thin-film cavitation1 lubrication with unsteady flow path changes.

This research method applies to automotive engines and all sliding component elements using fluid lubrication. It contributes to damage prediction and the development of safety guidelines for transportation and industrial machinery components, enabling the optimal design of components.

• The number of fatalities due to falling accidents indoor/outdoor has increased in Japan as well as in other advanced countries. The fatalities due to falling accidents in a year have exceeded those due to traffic accidents in Japan recently. Because more than 80% of the fatalities are elderly people, it is considered an urgent issue to prevent their falling. We have conducted researches on falling during walking due to induced slip, in the contact interface of shoe sole and floor, through tribological and biomechanical approaches. We clarified the required values of static friction coefficient (figure 1), between shoe sole and floor, and how to gait to prevent slipping through kinetic analysis of gait. We also succeeded in the development of a unique footwear outsole having the high-grip property (figure 2) and high slip-resistant concrete pavement blocks (figure 3) through the collaboration with regional companies. We have recently conducted research and development of footwear that is able to prevent falls due to balance loss after slipping.

Products for fall prevention in daily life or in work site. Evaluation of slip resistance of footwear and floor materials.

• A variety of new mobilities coexisting with humans, such as service robots, self-driving cars, and personal mobility, are expected to be deployed. In this laboratory, we are studying technologies for the safe and smooth coexistence of these various mobile vehicles with humans.
• In particular, we are approaching the problem from the aspect of predicting the movement of humans by considering their characteristics such as visual attention.

The targeted application is service robots, personal mobility, self-driving cars, and other mobile vehicles that will be expected to coexist with humans, as well as the design of transportation environments for these vehicles to safely coexist with humans.