汽車(chē)安全氣囊碰撞有限元分析外文翻譯-汽車(chē)設(shè)計(jì)-展示頁(yè)
2025-05-26 22:41本頁(yè)面
【正文】 e. The two springs can be fully restrained at their bases implying a perfectly rigid plastic housing. This is a good assumption when paring the flexibility of the thin springs to the stiff plastic housing. The ball can be represented by a rigid surface since it too is very stiff as pared to the springs. Rather than modeling the contact between the plastic housing and the ball, all rotations and translations are fully restrained except for the xdirection on the rigid surface representing the ball. These restraints imply that the housing Figure 2. Electromechanical sensor finite element mesh. will have no significant deformation due to contact with the ball. These restraints also ignore any gaps due to tolerances between the ball and the housing. The effect of friction between the ball and plastic is negligible in this sensor can be analyzed by applying an enforced displacement in the xdirection to the rigid surface representing the ball to simulate the full displacement of the ball. Contact between the ball and springs is modeled with various contact elements as discussed in the following section. A nonlinear static analysis is sufficient to capture the forcedisplacement response of the sensor versus using a more expensive and time consuming nonlinear transient analysis. Although the sensor is designed with a ball mass and spring stiffness that gives the desired response to a given acceleration, there is no mass associated with the ball in this static analysis. The mass of the ball can be determined by dividing the force required to deflect the springs by the acceleration input into the sensor. Mesh The finite element mesh for the sensor was constructed using MSC/PATRAN [2]. The solver used to analyze the sensor was MSC/ABAQUS. The finite element mesh including the contact elements is shown in Figure 2. The plastic housing was assumed to be rigid in this analysis and was not modeled. Both springs were modeled with linear quadrilateral shell elements with thin shell physical properties. The ball was assumed to be rigid and was modeled with linear triangular shell elements with Bezier 3D rigid surface properties. To model contact between the ball and spring1, rigid surface interface (IRS) elements were used in conjunction with the Bezier 3D rigid surface elements making up the ball. Linear quadrilateral shell elements with IRS physical properties were placed on spring1 and had coincident nodes with the quadrilateral shell elements making up spring1. The IRS elements were used only in the region of ball contact. To model contact between spring1 and spring2, parallel slide line interface (ISL) elements were used in conjunction with slide line elements. Linear bar elements with ISL physical properties were placed on spring1 and had coincident nodes with the shell elements on spring1. Linear bar elements with slide line physical properties were placed on spring2 and had coincident nodes with the shell elements making up spring2. Material Both spring1 and spring2 were thin metallic springs modeled with a linear elastic material model. No material properties were required for the contact or r
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