振动板速度最小化减振优化设计研究

减振设计是结构设计的重要内容之一，优化设计可在设计阶段通过对设计模型的定量修改获得理想的减振效果。基于有限元直接法计算振动板的频率响应，以板局部厚度为设计变量，计算了振动速度对局部板厚度的灵敏度；以振动板各节点振动速度的平方和最小化为目标，建立了减小振动板振动速度的减振优化数学模型，用可行方向法实现了优化。以一两端固支矩形板的振动为研究算例，对其在1Hz～200Hz的振动实施了优化；优化后振动板各节点在研究频率内的振动速度都得到了降低，降低最大值达0．311m／s。实例结果表明，优化设计通过对结构重量的重新分布可在结构重量相对不变的情况下，在一较宽频段内均得到减振效果。

STUDY ON REDUCING VIBRATION BY MINIMIZING VIBRATION VELOCITY OF A PLATE

Vibration veduction design of a plate is an important aspect of structure design, optimization can be achieved for a perfect vibration reduction by quantitative modification of its model in design phase. Its frequency response is calculated by use of FEM and its vibration velocity sensitivity with respect to its local thickness as a design variable is computed. An optimization model is set up with an objective function minimizing the square sum of vibration velocities of all nodes and an discretized frequencies. The optimization is performed by using the feasible direction method within frequency range of 1Hz~200Hz and a 0.331m/s max velocity reduction is achieved. Results show that plate optimization design of its weight redistribution has an remarkable effect on vibration reduction while its weight is almost unchanged.