Optimization of Nonlinear Vibration Characteristics for Seismic Isolation Rubber

A method for reducing the damage to a structure caused by an earthquake namely,using laminated rubber for seismic isolation is proposed,and the vibration characteristics of the rubber(which minimizes the seismic response of the structure during an earthquake)is optimized.A method called“Equivalent Linear System using Restoring Force Model of Power Function Type”(PFT-ELS)is applied to nonlinear vibration analysis of the rubber.In that analysis,a building with 15 layers of the laminated rubber is modeled.The seismic response of the building is analyzed,and the usefulness of the laminated rubber is demonstrated by comparing the seismic responses in the cases with and without the laminated rubber.In addition,the hysteresis restoring-force characteristic of the laminated rubber,which minimizes the seismic response of the building,was optimized by using a genetic algorithm(GA).Based on these results,the optimum restoring-force characteristic for different earthquakes was determined.As a result,it was clarified that the developed optimization method can determine the vibration characteristics of the laminated rubber for minimizing the damage to the structure in the design phase.

轿车发动机活塞冷却方法研究——第二部分 采用热管冷却活塞

在第一部分研究中,研究人员发现在高速往复运动状态下热管的导热系数有显著改善。然而,由于商用热管即使经受高速往复运动,其导热系数也不易提高,因而这种冷却方法很难应用到轿车发动机的活塞冷却。鉴于第一部分报告中的数据,本田公司技术中心决定开展轿车发动机活塞冷却用的热管设计研究,提出了1种最佳设计方案,并对它进行了热分析。结果发现,它可以将热量从必需冷却的活塞头中心区域传递到活塞裙部,显示了其有效冷却的可能性。虽然这种分析是基于一些假设,并且还存在因加装热管带来的耐久性和质量增加等问题,但通过创新努力可以将其拓展成为1种高级的发动机冷却系统。