钢板带板形瓢曲与翘曲变形行为研究

发布时间：2018-07-03 21:02

本文选题：钢板带 + 板形　；参考：《北京科技大学》2015年博士论文

【摘要】：随着航天航空、汽车、家电等高端制造业对板带产品质量要求日趋严格,板形成为影响产品竞争力和市场占有率的主要质量指标,板形生成理论与控制技术成为国内外研究前沿和热点。本文依托国家自然科学基金项目“超高强度钢板平整与矫直加工过程残余应力控制的基础研究”,采用解析、仿真和实验相结合的方法,对钢板带板形瓢曲和翘曲的生成机理与变形行为进行研究,以期发展和完善板形理论与技术。本文的主要内容及研究成果如下。 (1)针对板形平直性缺陷,依据其产生的力学机理,提出新的概括和分类,抽象建立板形瓢曲和翘曲的生成过程力学模型,推导建立可考虑钢板各向异性的通用解析计算模型及求解算法和初应变与外载荷作用下的样条有限元法计算模型及求解算法,编制MATLAB平台计算软件。经计算对比,两种方法的计算结果相互吻合并且都能满足板形研究需要。 (2)针对钢板带塑性压力加工初应变导致的板形平直性缺陷,应用所建立板形瓢曲和翘曲计算模型,深入研究了板形缺陷生成领域的三个重要问题。 ①研究轧后钢板各向异性及其对于板形平直性缺陷的影响,获得了瓢曲变形的屈曲临界载荷、临界波长、后屈曲路径和翘曲变形与钢板各向异性程度的关系,揭示了钢板各向异性对板形平直性缺陷的影响规律。 ②针对板带生产中多种不同板形斜向瓢曲现象,研究提出基于初应变或端部反对称拉伸叠加剪应力或中浪初应变叠加端部反对称拉伸或中浪初应变叠加剪应力等四种不同的生成机理解释,建立各自力学模型并实现求解,获得了斜向瓢曲的屈曲临界条件与后屈曲路径及其影响因素与变化规律。 ③针对一种复杂板形翘曲——反向C翘,建立力学模型,分析翘曲行为,获得吻合工业生产现象的变形规律,提出控制技术措施并取得成功。 (3)针对钢板带裁切加工过程结构改变导致板形变化,建模研究板形的演变规律。提出表观平直但有“潜”板形缺陷钢板裁切后翘曲变形的力学机理,计算获得裁切后各条翘曲与“潜”板形缺陷的关系；建立在线C翘切分后转化为离线L翘的力学模型,推导出转化关系公式,并获得实验验证。
[Abstract]:With the increasingly stringent requirements for the quality of strip products in high-end manufacturing industries such as aerospace, automobile, home appliances, and so on, flatness has become the main quality index affecting the competitiveness of products and market share. Flatness generation theory and control technology have become the research frontier and hot spot at home and abroad. Based on the National Natural Science Foundation project "basic Research on residual stress Control in Ultra-high strength Steel Plate leveling and straightening process", the method of combining analysis, simulation and experiment is adopted in this paper. The forming mechanism and deformation behavior of plate shape buckling and warping are studied in order to develop and perfect the shape theory and technology. The main contents and results of this paper are as follows: (1) according to the mechanical mechanism of flatness defects, a new generalization and classification is proposed, and a mechanical model of the generating process of plate shape buckling and warping is established abstractly. A general analytical calculation model and algorithm for plate anisotropy and spline finite element method under initial strain and external load are derived and the MATLAB software is developed. By calculation and comparison, the results of the two methods are consistent with each other and can meet the needs of shape research. (2) aiming at the flatness defect caused by the initial strain of plastic pressure working of steel plate, In this paper, three important problems in the field of shape defect generation are studied by using the calculation model of plate shape buckling and warping. 1 the anisotropy of rolled steel plate and its influence on flatness defect are studied. The critical buckling load, critical wavelength, post-buckling path, warping deformation and anisotropy of steel plate are obtained. The influence of anisotropy of steel plate on flatness defect is revealed. Based on four different generation mechanisms of initial strain or end antisymmetric tensile superposition shear stress or middle wave initial strain superposition end antisymmetric tension or intermediate wave initial strain superposition shear stress, the mechanical models are established and solved. The critical buckling conditions and post-buckling paths of oblique buckling are obtained, and the influencing factors and changing rules are obtained. 3 for a complex shape warpage-reverse C-warping, a mechanical model is established to analyze the warpage behavior. The deformation law consistent with the industrial production phenomenon is obtained, and the control technical measures are put forward with success. (3) in view of the shape change caused by the structural change in the cutting process of the steel strip, the shape evolution law of the plate shape is studied by modeling. This paper puts forward the mechanical mechanism of the warpage deformation after cutting the steel plate with apparent straight but "submerged" shape defects, calculates the relationship between the warpage after cutting and the "submersible" shape defect, and establishes a mechanical model that can be transformed into off-line L warping after on-line C-warping. The formula of transformation relation is deduced and verified by experiment.
【学位授予单位】：北京科技大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TG334.9

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