双激励超声波椭圆振动磨削装置设计及优化

基于ANSYS Workbench多目标驱动模块对双激励超声波椭圆振动磨削(UEVG)装置进行优化设计。基于等效电路法设计前盖板是λ/4(λ为波长)复合变幅杆的半波长换能器,先后建立带有载物台的变幅杆及UEVG装置的参数化模型进行模态、谐响应分析。根据10个设计点模态分析确定变幅杆最优尺寸,在此基础上通过42个设计点仿真分析获得UEVG装置的谐振频率、节面位置与结构尺寸的关系,并优化尺寸。优化后UEVG装置的谐振频率与理论设计频率的误差为0.24%,振幅高达16.7μm。     

超声辅助加工中磨削热模型的建立与验证

对超声振动辅助磨削碳纤维复合材料过程中产生的磨削热进行研究。在特定的条件下,建立了相应的磨削热传递模型并对此模型进行了有限元仿真;在相同的条件下,通过工件上布置的光纤光栅传感器测量超声振动辅助磨削碳纤维复合材料在实际加工中产生的磨削温度。对比仿真与实验结果,验证了磨削热传递模型的正确性。结果表明:磨削热传递模型可以很好地预测磨削过程中热量的传递状态,为后续优化实验参数、提高工件表面质量提供了理论依据,具有较高的实用价值。     

Experimental study on cross-sensitivity oftemperature and vibration of embedded fiber Bragg grating sensors

In view of the principle for occurrence of cross-sensitivity, a series of calibration experiments are carried out to solve the cross-sensitivity problem of embedded fiber Bragg gratings (FBGs) using the reference grating method. Moreover, an ultrasonic-vibration-assisted grinding (UVAG) model is established, and finite element analysis (FEA) is carried out under the monitoring environment of embedded temperature measurement system. In addition, the related temperature acquisition tests are set in accordance with requirements of the reference grating method. Finally, comparative analyses of the simulation and experimental results are performed, and it may be concluded that the reference grating method may be utilized to effectively solve the cross-sensitivity of embedded FBGs.