切削测力平台结构递进式拓扑优化设计研究

Research on the Progressive Topology Optimization of Cutting Force Platform Structure

微切削加工过程中,切削力是影响加工质量的重要参数。测力仪是动态测量切削力的主要装置,其测力平台部分工作稳定性和准确性对测力仪整体性能起到决定性作用。目前使用的大部分测力平台设计均可以满足宏观较大振幅应力测量要求,但较差的灵敏度和严重的信号衰弱无法满足微切削状态下切削力的微小变化测量。因此提出了一种在满足测力平台弹性体结构强度等要求下,首先以固有频率为目标函数进行单目标优化,将优化后的固有平率作为约束条件,再以应力集中为目标函数进行二次优化的递进式拓扑优化方法;并对优化后的结构进行模态试验,从而证明采用递进式拓扑优化的结构设计方法可以极大的提高测力平台工作时的稳定性、灵敏度和测量精度等性能,同时也拓展了测力平台微切削条件下的适用性。

The cutting force is an important parameter that affects the machining quality in micro-machining process.Besides that,the dynamometer is the main device for measuring the cutting fore.The stability and accuracy of the fore-measuring platform plays a decisive role in the whole performance of the dynamometer.At present,most of the designs of the fore-measuring platform can measure the cutting force with a large amplitude,but due to the poor sensitivity and severe signal weakness of the platform,the micro-machining with small changes of the cutting fore can not be measured.As a result,an ideal of the design is putted forward that the natural frequency is used as the objective function to have a single objective optimization at first,and then,a further optimization with the constraint condition of natural frequency which has been optimized has been carried with the objective function of stress concentration.Lastly,the modal test of the optimized structure is carried out to prove that the structure design method based on progressive topology optimization can greatly improve the stability,sensitivity and measurement accuracy of the working platform.In addition,it also expands the applicability of force platform in the micro-machining condition.