300M超高强钢高温本构模型的研究

发布时间：2019-05-21 09:06

【摘要】：随着技术的革新，物理模拟和数值模拟技术在各个研究领域都获得了越来越广泛的应用，而模拟的精度，则取决于材料的本构模型，因此，材料的本构关系一直是材料与力学领域研究的热点。300M超高强度钢具有良好的力学综合性能，被大量应用于飞机的承力构件上。通过相应的资料可以了解到300M钢的室温力学性能数据，但是关于该材料高温塑性变形时的流变应力的研究还很不足。本文主要对300M钢的热变形本构模型以及金属切削变形本构模型进行研究。论文的主要研究内容包括：首先，通过在热模拟试验机上进行高温压缩实验，得到300M钢在一定变形条件范围内的应力-应变曲线，结合实验结果分析各热变形参数对流变应力的影响，结果表明：在应变速率不变的情况下，随着温度的升高，流变应力显著减小；在温度不变的情况下，随应变速率的增大流变应力也随之增大。其次，以高温热压缩实验得到的数据为基础，进行热变形本构模型的研究，分别应用Arrhenius方程以及BP神经网络两种方法建立300M钢的热变形本构模型，以表达流动应力与变形温度及应变速率的关系。通过预测出的流变应力值及其变化趋势，分析评价以上两种模型，，并指出两种模型的优劣点。最后，分析并指出热变形本构模型与金属切削模型之间的区别，并结合现有的切削变形本构方程及实验方法，依据实验目的以及现有的实验条件，采用实验与切削理论分析相结合的方法，确定求解Johnson-Cook模型的建模路线，即利用准静态压缩实验以及正交切削实验，通过对实验结果的处理、计算，分别得到Johnson-Cook本构关系式中的五个系数的值，从而得到300M钢的Johnson-Cook本构关系方程式。并基于AdvantEdge FEM软件，导入求得的Johnson-Cook本构关系，对正交切削过程进行仿真模拟，通过仿真结果来验证本构模型的准确性。
[Abstract]:With the innovation of technology, physical simulation and numerical simulation technology have been more and more widely used in various research fields, and the accuracy of simulation depends on the constitutive model of materials. Therefore, The constitutive relation of materials has always been a hot research topic in the field of materials and mechanics. 300m ultra-high strength steel has good mechanical comprehensive properties and has been widely used in aircraft load-bearing components. The mechanical properties of 300m steel at room temperature can be obtained from the corresponding data, but the research on the Rheological stress of 300m steel during plastic deformation at high temperature is still very insufficient. In this paper, the hot deformation Constitutive Model and Metal cutting deformation Constitutive Model of 300m Steel are studied. The main research contents of this paper are as follows: firstly, the stress-strain curve of 300m steel in a certain range of deformation conditions is obtained by high temperature compression experiment on a thermal simulation testing machine. Combined with the experimental results, the influence of convective stress on each thermal deformation parameter is analyzed. the results show that the flow stress decreases significantly with the increase of temperature when the strain rate is constant. When the temperature is constant, the flow stress increases with the increase of strain rate. Secondly, based on the data obtained from high temperature hot compression experiment, the hot deformation constitutive model of 300m steel is studied, and the hot deformation constitutive model of 300m steel is established by using Arrhenius equation and BP neural network, respectively. To express the relationship between flow stress and deformation temperature and strain rate. By predicting the Rheological stress value and its changing trend, the above two models are analyzed and evaluated, and the advantages and disadvantages of the two models are pointed out. Finally, the difference between the thermal deformation constitutive model and the metal cutting model is analyzed and pointed out, and combined with the existing cutting deformation constitutive equation and experimental method, according to the experimental purpose and the existing experimental conditions, By using the method of combining experiment with cutting theory analysis, the modeling route of solving Johnson-Cook model is determined, that is, by using quasi-static compression experiment and orthogonal cutting experiment, the experimental results are processed and calculated. The values of five coefficients in the Johnson-Cook Constitutive relation are obtained respectively, and the Johnson-Cook Constitutive relation equation of 300m steel is obtained. Based on AdvantEdge FEM software, the Johnson-Cook constitutive relation is introduced to simulate the orthogonal cutting process, and the accuracy of the constitutive model is verified by the simulation results.
【学位授予单位】：哈尔滨理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG142.1

【相似文献】