Search Results

With a view to simplifying the simulation models and shortening the computation periods, the author extends the building block approach (BBA), which is commonly applied to linear analysis with the finite element method, to non- linear areas, and applies the extended BBA to drivetrains. When the frequency of the vibration being studied is more or less known, the restrictions of the conventional vibration mode selection method are shown to be significantly relaxed by the modal compensated method described in this paper. Further, when the BBA is applied to time-response analysis and the effect of a decrease in freedom and the time-step-expansion effect of the removal of high- order components are analyzed, the effect of removal of high-order components is shown to be particularly great. Also, an increase in the intensity of nonlinearity necessitates a smaller time step with the conventional method, whereas the time step with the BBA is hardly affected by the intensity of nonlinearity.

Since it is more difficult for truck door panels to realize curvature than passenger car door panels, internal stiffeners are mounted between the outer panel and inner panel through the use of an adhesive for ensuring stiffness. For this reason, a problem occurs as to the proper placement of the stiffeners so as to effectively improve stiffness. By FEM prediction and experimentation, the following have been clarified: (1) Arrangement of stiffeners for effectively improving stiffness (2) Stiffness share of stiffeners and outer panel against stiffness

Generation mechanism and characteristics of idling rattle are systematized analytically by experiments on vehicle and digital simulation of nonlinear torsional vibration system for an inline four-cylinder four-cycle compact diesel engine. Jumping and hysteresis of the noise level are caused by both decreasing engine torque fluctuations while engine rotating velocity increases, and clutch-disc torsional characteristics of two-staged hardening spring. An improved clutch disc with a decreased noise level of 5 dB (A) was developed clarifying the optimum combination of disc characteristics, and permitting engine rotating velocity, where jumping occurs, below idling rotating velocity.