拉杆螺纹在偏载下的应力分析  

Stress analysis of tie-bar threads under oblique load

作　　者：周雄新[1] 欧笛声[1] 

机构地区：[1]广西工学院工程训练中心,柳州545006

出　　处：《机械设计与制造》2012年第6期212-213,共2页Machinery Design & Manufacture

基　　金：广西壮族自治区科技厅青年基金项目(桂科青0728013);广西教育厅科研项目(201106LX422)

摘　　要：针对因注塑机各模板变形而引起拉杆承受附加弯矩的问题,采用ANSYS内嵌的APDL语言建立拉杆梯形螺纹、卸载槽及螺母和调模板的有限元分析模型,运用有限元的非线性算法,分析拉杆梯形螺纹在偏载下的应力分布。计算结果表明:拉杆梯形螺纹近卸载槽的22个牙型左侧根部及与螺母配合的12个牙型左、右侧根部的最大等效应力均超过材料屈服极限,在变载的作用下均有可能因微小裂纹的扩展而导致拉杆断裂。最后分析了偏载发生的原因并据此提出改善措施。Due to additional bending moment on tie bar caused by the deformation of injection molding machine platens,a finite element model of trapezoidal thread of the tie bar,unloading groove as well as a nut and a mould board was built using ANSYS embedded APDL language,and the stress distribution of trapezoidal thread under oblique loading is analyzed by using the nonlinear computation method.The calculation results show that： the maximum equivalent stress at the left root of 22 teeth near unloading groove and at the left,right root of 12 teeth matched with a nut are greater than the yield limit of material.The variable load under the action of small crack growth may bring about the tension tie-bar rupture.At last the causes of oblique load were analyzed and the improvement measures were put forward accordingly.

关 键 词：注塑机 梯形螺纹 偏载 应力分析 

分 类 号：TH16[机械工程—机械制造及自动化] TG457.22[金属学及工艺—焊接]