镀锌钢压印接头结构参数及力学性能的研究

发布时间：2018-04-08 23:30

  本文选题：压印连接　切入点：失效模式　出处：《昆明理工大学》2017年硕士论文

【摘要】：中国制造2025的提出,不仅提出对制造业实现数字化、网络化和智能化的要求,而且在发展制造业的同时强调破解环境和资源制约,特别提到节能减排,其中节能与新能源汽车是中国制造2025十大重点领域之一。在探索实现汽车的节能减排的道路上,结构轻量化是行之有效的方法之一。但在实现结构轻量化的过程中,轻量金属的连接技术是亟待解决的问题。近些年国内已经对新型板材连接技术展开研究,包括本文的研究核心:压印连接技术。之前对于压印连接技术的研究侧重于压印接头的力学性能和不同材料的压印接头的相似与不同之处,但对于压印接头在失效过程中的规律和失效模式研究较少。本文主要的试验对象为压印接头,通过大批量的试验对压印接头的失效模式和其中规律进行分析研究。具体的研究内容包括:1)本文根据传统失效模式的定义,探究发现压印接头产生不同失效模式的根本原因是上板颈部强度与内锁强度两种结构强度之间的博弈。本文从传统失效模式中区分出混合失效并发现其优越性;2)其次,根据之前学者的相关研究并结合在试验中的经验,在论文中提出压印接头变化的数值变量并将其命名为压印结构系数s,s是由颈部厚度tN和镶嵌量tU相除得到的;3)在镀锌钢同种接头拉伸-剪切试验结果中,根据结构系数s的变化可预测压印接头的失效模式。当s的值小于0.50时,所有接头的失效模式均为上板颈部断裂失效模式;当s的值在2.35到7.00变化时出现的失效模式几乎为混合失效当s的值从8.60趋向于∞时,接头的失效模式逐渐由混合失效向上板拉脱失效变化;出现颈部断裂失效接头个数随s的值呈线性下降的趋势,出现混合失效接头个数随s的值呈近似抛物线的趋势,出现拉脱失效接头个数随s的值呈线性上升的趋势。当s的值为4.40时,此时压印接头的承载能力是最高的,当s的值为5.70时,此时压印接头的能量吸收值是最高的;同时8组试验组的承载能力和能量吸收值随着s值增大呈现抛物线状变化;4)在得到镀锌钢同种压印接头失效过程中有关s值的规律后利用验证组试件,对所得的规律进行验证。验证结果发现,所得规律在同质压印接头的DP590-DP590和SPCC-SPCC接头得到验证,但对于异质接头TA1-1420接头规律明显不适用;5)在动态疲劳试验中,选取了混合失效失效模式和上板颈部断裂失效模式的压印接头。发现结构系数s和压印接头动态疲劳性能两者存在线性关系,即随着压印结构系数s的增大压印接头动态疲劳性能逐渐下降,在s=0.5时可取得最佳疲劳强度的镀锌钢接头。
[Abstract]:The proposal of the made in China 2025 not only puts forward the requirement of digitizing, networking and intelligentizing the manufacturing industry, but also emphasizes on solving the environmental and resource constraints while developing the manufacturing industry, with particular reference to energy saving and emission reduction.Energy-saving and new energy vehicles are made in China in 2025, one of the top ten key areas.Structural lightweight is one of the effective methods to realize energy saving and emission reduction.However, in the process of structural lightweight, the connection technology of light metal is an urgent problem to be solved.In recent years, a new type of plate bonding technology has been studied, including the core of this paper: imprint connection technology.The previous research on imprint connection technology focused on the mechanical properties of the imprint joint and the similarity and difference of the imprint joint with different materials, but there was little research on the rule and failure mode of the imprint joint during the failure process.The main test object in this paper is the imprint joint. The failure mode and the regularity of the imprint joint are analyzed and studied by mass test.In this paper, according to the definition of traditional failure mode, it is found that the fundamental reason for different failure modes of imprint joint is the game between the strength of upper plate neck and the strength of inner lock.This paper distinguishes the mixed failure from the traditional failure mode and finds its superiority. Secondly, according to the relevant research of previous scholars and combined with the experience in the experiment,In this paper, the numerical variable of the change of the imprint joint is proposed and named as the imprint structure coefficient SKS is obtained by dividing the thickness of neck t N and the amount of tu inlay) in the tensile shear test results of galvanized steel joint of the same kind.According to the change of structure coefficient s, the failure mode of imprint joint can be predicted.When the value of s is less than 0.50, the failure mode of all joints is the failure mode of neck fracture of upper plate, and the failure mode when the value of s varies from 2.35 to 7.00 is almost mixed failure when the value of s tends to 鈭，

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