摘要
对双金属复合管单位长度质量的等效截面抗弯曲、抗拉压、抗扭刚度进行了推导。分析了钢-铜、钢-铝双层、铜-钢-铜三层双金属复合管在不同结构和尺寸组合时,其各等效截面刚度与同规格单金属管各截面刚度之比随内层管与总管壁厚之比n的变化规律。获得了最优刚度性能的复合管最佳结构与尺寸组合,能节约贵金属材料。采用等效截面抗弯曲刚度、等效截面抗拉压刚度、等效质量法,推导出双金属复合管弯曲振动和轴向振动固有频率的计算模型;采用等效截面抗扭刚度、等效质量并结合等效转动惯量法,推导出其扭转振动固有频率计算模型。复合管前三阶固有频率的计算值与有限元值相比,最大误差为2.35%;与实测值相比,最大误差为3.15%。研究结果表明:内铝、外钢复合管在抗弯、抗扭方面(n=0.63时)存在最优结构。
The equivalent cross-sectional bending stiffness, tension-compression stiffness and torsion stiffness of bimetallic tubes are analyzed. The variations of respective equivalent cross-sectional specific stiffness of bimetallic tubes with the thickness ratio n(the ratio of the inner tube wall thickness to the total wall thickness) are obtained for different structures and geometry. With steel-copper, steel-aluminum and copper-steel-copper composite tubes as calculation examples, the optimal structure and size combinations of bimetallic tubes are investigated, which can meet the technical requirements, save precious metals, and has optimal stiffness properties. Theoretical models of bending and axial vibration frequencies are deduced for bimetallic tubes by adopting methods of equivalent cross-sectional bending stiffness, equivalent cross-sectional tensile stiffness and equivalent mass. The calculation method of natural torsion vibration frequency is also established for bimetallic tubes, by using equivalent cross-sectional torsion stiffness and equivalent mass and equivalent inertia moment. The calculated values of the first three natural frequencies of bimetallic tubes are compared with the finite element values, the maximum error is of 2.35%, while compared with the measured values, the maximum error is of 3.15%.
出处
《应用力学学报》
CAS
CSCD
北大核心
2016年第1期168-174,190,共7页
Chinese Journal of Applied Mechanics
基金
山西省自然科学基金(2013011025-2)
关键词
双金属复合管
等效截面刚度
等效质量
固有频率
bimetallic tubes
equivalent cross-sectional stiffness
equivalent mass
natural frequencies
