上机匣筋部成形过程的数值模拟

Numerical simulation on forming process of rib portion of upper case

采用刚塑性有限元法对径向筋条的成形过程进行了模拟， 结果表明， 锻造时， 金属首先充填轴套部分， 轴套部分基本充满后才开始充填筋部， 且筋条的充填顺序为由里到外， 外侧顶部为最后充填处。在变形终了阶段， 腹板与轴套交界处出现剧烈的剪切流动， 有可能造成组织缺陷。根据模拟结果， 锻造时采取了特殊措施， 成功地锻制出上机匣锻件， 锻件的力学性能。

The forming process of radial rib of upper case is simulated by the rigid plastic finite element method. It can be seen that, in the forming process, the metal fulfill the axial ring first, then fulfill the rib. The sequence of metal fulfillment is from the inner to the outer and the upper portion of the outer is fulfilled lastly. In the final stage of forming, the severe shear flow presents at the joint portion of web and axial ring which is of the possibility for generating the defects of microstructure. According to the simulating result, some special means are adopted and the forging of upper case is conducted successfully. Both the mechanical properties, microstructure and the accuracy of forging satisfy the requirements of the user