基于Dynaform的小车前门外板冲压工艺参数的优化

发布时间：2019-07-06 19:41

【摘要】：小汽车车身主要是板料覆盖件,且由冲压模具冲压而成,其质量的好坏会影响到汽车整车的质量。板料冲压成形过程中除了需要考虑板材的力学性能之外,还需要有合理的成形工艺参数。本文针对某小车前门外板冲压成形过程中可能出现缺陷的主要原因,采用数值模拟方法对影响成形质量的冲压工艺参数进行分析和优化,从而来避免这些缺陷的产生,达到提高产品质量,降低成本的目的。本文以板料在冲压成形的力学理论和有限元数值模拟理论为基础,采用非线性有限元软件Dynaform对某型号小车前门外板的冲压工艺参数进行了数值模拟分析和研究。本文主要研究内容如下:(1)运用板料成形的数值模拟方法,对小车前门外板的结构工艺特点进行了分析,并建立起小车前门外板的有限元模型。(2)运用Dynaform对小车前门外板的有限元模型进行了冲压成形的数值模拟,获得了成形后的应力图、应变图、厚度变化图以及成形极限图,从图中根据成形极限指标评估了工件的冲压状况,还预测了产品某些部位可能出现的缺陷:起皱、拉裂等,并分析了产生这些缺陷的主要原因。(3)通过研究压边力、摩擦系数、板料厚度和冲压速度等工艺参数对产品冲压成形过程的影响规律,运用Dynaform软件数值模拟的结果,分别确定了这四个冲压工艺参数的合理取值范围。(4)运用正交试验方法对小车前门外板冲压工艺参数进行试验设计。从试验结果中提取最大减薄率和最大增厚率两个指标,获得板料成形冲压工艺参数的较优组合,并将优化后的冲压工艺参数进行数值模拟,模拟的结果证明了优化结果的合理性和优化方法的可靠性。
文内图片：

图片说明：图２．１应力－应变图逡逑Ｆｉ．２．１邋ｓｔｒｅｓｓ－ｓｔｒａｉｎ邋ｄｉａｒａｍ逡逑
[Abstract]:The car body is mainly sheet metal panel, and is made of stamping die. The quality of the car body will affect the quality of the whole car. In the process of sheet metal stamping, not only the mechanical properties of sheet metal need to be considered, but also reasonable forming process parameters are needed. In view of the main causes of defects in the stamping process of the outer plate of the front door of a car, this paper analyzes and optimizes the stamping process parameters that affect the forming quality by using the numerical simulation method, so as to avoid the occurrence of these defects and achieve the purpose of improving the product quality and reducing the cost. Based on the mechanical theory and finite element numerical simulation theory of sheet metal forming, the stamping process parameters of the front door outer plate of a certain type of trolley are analyzed and studied by using the nonlinear finite element software Dynaform in this paper. The main contents of this paper are as follows: (1) the structural and technological characteristics of the outer plate of the front door of the car are analyzed by using the numerical simulation method of sheet metal forming, and the finite element model of the outer plate of the front door of the car is established. (2) the finite element model of the outer plate of the front door of the car is used to simulate the stamping forming of the outer plate of the front door of the car, and the stress diagram, strain diagram, thickness change diagram and forming limit diagram after forming are obtained. According to the forming limit index, the stamping condition of the workpiece is evaluated, and the possible defects in some parts of the product, such as wrinkling and cracking, are predicted, and the main causes of these defects are analyzed. (3) by studying the influence of blank holder force, friction coefficient, sheet metal thickness and stamping speed on the stamping process of the product, the results of numerical simulation with Dynaform software are carried out. The reasonable range of the four stamping process parameters is determined respectively. (4) the orthogonal test method is used to design the stamping process parameters of the front door outer plate of the trolley. The maximum thinning rate and the maximum thickening rate are extracted from the experimental results, and the optimal combination of the stamping process parameters of sheet metal forming is obtained. The optimized stamping process parameters are simulated by numerical simulation. The simulation results prove the rationality of the optimization results and the reliability of the optimization method.
【学位授予单位】：中南林业科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U466;TG386

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