22MnB5矩形管弯曲成形极限研究

发布时间：2018-07-10 14:43

本文选题：22Mn + B5　；参考：《哈尔滨工业大学》2015年硕士论文

【摘要】：22Mn B5是一种高强钢材料,由22Mn B5加工的矩形管应用于客车车身骨架中,可以在保证汽车安全强度的同时显著减轻其重量,达到节能减排的目的。随着矩形管弯曲半径逐渐减小,管材容易产生内壁增厚起皱,外壁减薄破裂,横截面畸变等缺陷。因此掌握22Mn B5矩形管的弯曲成形规律,获得矩形管弯曲成形极限对指导矩形弯管零件的设计和加工都有非常重要的意义。基于塑性力学的基本理论,分析了矩形管弯曲时的应力应变分布。考虑到矩形管绕弯过程中受到的切向拉力作用,推导了矩形管弯曲时的应力应变关系式和应变中性层位置。研究了弯曲时切向拉力对弯管应变中性层和应变的影响规律。提出了22Mn B5矩形管弯曲成形极限的评价标准和预测方法。进行材料拉伸试验,获得了管材上22Mn B5材料的本构关系及22Mn B5不同热处理状态、厚度的成形极限平面应变点,确定了矩形管弯曲成形极限的影响因素。利用ABAQUS有限元仿真软件的Explicit算法,建立了矩形管绕弯的仿真模型。对不同弯曲参数的矩形管绕弯过程进行了有限元仿真计算。分析了22Mn B5矩形管绕弯成形规律,获得了矩形管切向应变和应变中性层与弯曲参数的关系,结合理论解析建立的管材弯曲成形极限预测方法,获得了不同材料热处理状态、几何参数和摩擦力影响下的22Mn B5矩形管弯曲成形极限及不同参数对矩形管弯曲成形极限的影响规律。通过试验数据、数值模拟、理论解析结果的比较分析,验证了数值模拟模型,理论解析和数值模拟获得的管材弯曲规律及管材弯曲成形极限模拟结果的正确性。
[Abstract]:22MnB5 is a kind of high strength steel material. The rectangular tube processed by 22MnB5 is applied to the frame of bus body, which can reduce the weight of the bus body while ensuring the safety strength of the bus, and achieve the purpose of energy saving and emission reduction. With the decrease of bending radius of rectangular tube, inner wall thickening and wrinkling, outer wall thinning and cracking, cross section distortion and so on are easy to occur. Therefore, it is very important to master the bending forming law of 22MnB5 rectangular tube and obtain the bending forming limit of rectangular tube for guiding the design and machining of rectangular tube bending parts. Based on the basic theory of plastic mechanics, the distribution of stress and strain in rectangular tube bending is analyzed. Considering the tangential tension in the bending process of rectangular tube, the stress-strain relation and the position of strain neutral layer are derived. The influence of tangential tension on the strain neutral layer and strain of bend tube was studied. The evaluation standard and prediction method of bending forming limit of 22MnB _ 5 rectangular tube are presented. The constitutive relation of 22MnB5 material on the tube and the forming limit plane strain point of the thickness of 22MnB5 in different heat treatment state were obtained, and the influencing factors of the forming limit of the rectangular tube were determined. By using explicit algorithm of Abaqus finite element simulation software, the simulation model of rectangular tube bending is established. The bending process of rectangular tube with different bending parameters was simulated by finite element method. The forming law of 22MnB5 rectangular tube is analyzed, the relationship between tangential strain and strain neutral layer and bending parameters is obtained, and the heat treatment state of different materials is obtained by using the limit prediction method established by theoretical analysis. The bending forming limit of 22MnB5 rectangular tube under the influence of geometric parameters and friction force and the influence of different parameters on the bending forming limit of rectangular tube are studied. Through the comparison and analysis of experimental data, numerical simulation and theoretical analytical results, the correctness of the numerical simulation model, theoretical analysis and numerical simulation results of pipe bending and the ultimate simulation results of tube bending are verified.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG306

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