GSA70型铝制罐车车体基于温差应力有限元分析和探讨

Finite Element Analysis and Discussion of GSA70 Type Aluminum Tank Body Based on Temperature Difference Stress

针对不同材料接触面计算时选用几种模拟连接的模型处理方法,其中采取接触单元方法,计算结果和车体静强度试验值接近,因此接触单元方法合理。针对GSA70型铝制罐车运用中产生温差应力的问题,利用接触单元模拟连接方法进行车体基于温差应力的有限元计算,在每个单元加载温差载荷,在释放罐体端部支座与底架的纵向约束的前提下,各运行工况罐体的主应力值满足了考核指标的要求。端部支座与底架因温差应力产生的纵向相对变形,通过有限元分析利用接触单元模拟连接方法计算出变形量,确定了端部支架紧固螺栓孔的间隙;然后进行反复的有限元迭代分析,得出因温差应力产生罐体端部支座与底架之间的纵向力,纵向力与螺栓紧固而产生的摩擦力相平衡,进而确定了紧固螺栓的预紧力及螺栓拧紧力矩。采用适合的螺栓孔间隙和螺栓拧紧力矩,可以释放铝制罐车车体的温差应力。

Several model processing methods of simulating connection were selected for the calculation of contact surfaces of different materials,among which the contact element method was adopted.The calculated results were close to the static strength test value of the vehicle body,so the contact element method was reasonable.For GSA70 type aluminum tank car used in the problem of temperature stress,using the contact element to simulate the connection method of car body based on the finite element calculation of temperature stress and temperature load in each unit load,the release of end bearing with chassis longitudinal constraint of tank under the premise of the operation condition of principal stress of tank value meet the requirements of the assessment index.The longitudinal relative deformation of the end support and the bottom frame due to the temperature difference is calculated by using the contact element simulation connection method through finite element analysis,and the clearance of the bolt hole of the end support fastening is determined.Then repeated finite element iterative analysis was carried out to obtain the longitudinal force between the tank end support and the bottom frame due to the temperature difference stress,and the longitudinal force was in balance with the friction caused by bolt fastening,and then the pre-tightening force and tightening torque of the bolt were determined.The suitable bolt hole clearance and bolt tightening torque can release the temperature difference stress of aluminum tank body.