On the use of fixed point theory to design coupled core walls
The use of Fixed Point Theory (FPT) to optimize the design of coupling beams in coupled core wall (CCW) systems is demonstrated. The basis for optimization is minimizing the transmissibility of horizontal ground motion by appropriately linking two coupled wall piers having different dynamic properties with beams having appropriate stiffness and damping characteristics. Using 21 example CCW structures illustrating a range of pier properties, it was shown that the resulting optimization of coupling stiffness is quite small and other design considerations will require stiffer, non-optimal coupling beams. Nonetheless, the potential to leverage the small amount of coupling available in a ‘slab-coupled’ series of wall piers in order to reduce transmissibility is suggested by the findings of this study.
Method of Estimating Equivalent Mass of Multi-Degree-of-Freedom System
To attain the optimum design of vibration controllers to suppress the many resonance peaks of machine structures, it is necessary to know the equivalent mass at the location at which the controller is mounted. This paper shows two ways of estimating equivalent mass, one is a modal analysis method, and the other is called the mass response method which utilizes the change in natural frequency of a structure when an additional mass is attached. The first method is useful for identifying a modal mass having a physical meaning, while the other method is more suitable for application to experimental analysis. The accuracy of these methods are compared by applying them to three kinds of mechanical structure.
Laminar heat or mass transfer in rectangular channels and in cylindrical tubes for fully developed flow: comparison of solutions obtained for various boundary conditions
Abstract A comparison is made of results obtained with various boundary conditions at the wall of the channels. By comparing blood Sherwood numbers for finite wall resistance with those for constant concentration boundary condition only a small variation is found for various points along the blood channel.