SiC_p/Al复合材料薄壁板钻削过程中的动力学特性变化研究

Study on Change of Dynamic Characteristics of SiC_p/Al Composites Thin Walled Plate in Process of Drilling

应用ABAQUS软件仿真研究钻削过程对高体分小颗粒SiCp/Al复合材料薄壁板固有特性变化的影响。结果表明:钻削过程中内孔的结构变化对试件固有频率和振型影响不大,钻孔前和钻孔后试件前5阶的固有频率均随厚度的增加呈直线上升趋势。在钻孔直径较小时,钻孔直径对固有频率影响不大;当钻孔直径超过试件边长的1/3时,第1阶固有频率随钻孔直径呈明显上升的趋势,其余4阶固有频率在钻孔直径大于试件边长的1/2后,随钻孔直径的增大而增加;当钻孔直径小于30mm时,试件第1阶固有振型为整体振动,钻孔直径达40mm后,第1阶振型呈弧形局部振动,试件2~5阶为局部振动,且在钻孔直径大于一定值后,振型向局部弧形振动变化。试件厚度对固有振型的影响不大。

ABAQUS software is used to simulate the influences of drilling process on the natural characteristics of SiCp/Al composites thin walled plate with high volume fraction and small particle sizes.The results show that the structural variation of inner hole has little effect on the natural frequency and vibration mode of the specimen.Before and after the drilling,the first five orders natural frequency of specimen is increased linearly with the increase of the thickness.When the diameter of drilling hole is small,the effect of diameter on the natural frequency is not large.When the diameter exceeds the 1/3 length of the specimen,the first order natural frequency shows obvious rising trend with the increase of diameter.When the diameter exceeds the 1/2 length of the specimen,the other four orders natural frequencies are increased with the diameter.When the diameter is less than 30mm,the first order natural vibration mode of the specimen demonstrates the overall vibration.After the diameter reaches 40mm,it shows local arc vibration.From the second order to the fifth order,the vibration mode of specimen all show local vibration,and the vibration pattern changes to local arc vibration when the diameter is larger than a certain value.The thickness of specimen has little effect on the natural vibration mode.