发动机缸体主轴承座及主轴承盖的动态应力和温度测量

为评估某直列6缸柴油机缸体有限元强度分析结果,采用应变电测法实测了该发动机缸体上可能的危险部位主轴承座、主轴承盖动态应力以及这些部位的温度。在缸体上布置了5个测点,对各贴片处进行了专门加工;选用了中温应变片及应变胶,并对各贴片进行了加温固化和耐油处理。实测中应变补偿片只能置于室温环境,之后根据所测温度考虑了应变片热输出,从而得出各测点动态应力结果。试验结果表明,该测量方案可用于测量发动机缸体、缸盖等中高温零部件的动态应力和温度。

Measurement of Dynamic Stresses and Temperatures of Main Bearing Walls and Caps on an Engine Block

To validate the FEM calculations of the cylinder block of a six-cylinder in-line diesel engine,the dynamic strain-stress and temperatures of the main bearing walls and caps were measured on engine testbed with strain-gauge and resistance thermometer.All of five measure points were specially machined for affixing the strain-gauges and wire leading.Considering the temperature and oil inside the block,middle-temperature strain-gauges and strain glue were used,the gluing of strain-gauges on engine block was solidified under a heating condition,and oil proof measures were taken.During the measurement,strain-gauges for compensation had to be with a environmental temperature.Then thermal output of strain-gauge were taken into account according to the temperatures measured,and hence mechanical strains and stresses of the engine block were reached.The method described in the paper can be adopted to measure the dynamic stresses and temperatures of engine components with middle or high temperature as block and cylinder head.