【作者】 杨韬；

【导师】 冯然； 郭伟明（Quach Wai-Meng）；

【作者基本信息】 哈尔滨工业大学 ， 建筑与土木工程（专业学位）， 2021， 硕士

【摘要】 3D打印技术基于计算机三维辅助设计及分层叠加制造原理,极大地颠覆了传统金属制造业生产模式,能够实现任意几何形状的复杂金属构件高精度快速成形。在建筑钢结构件生产中,相较于热轧、冷成型、铸造、焊接等传统钢结构制造工艺,3D金属打印技术提供了极大的设计自由,同时其工艺周期短、材料强度高、成形质量精度高、能源投入和对环境影响小,具有诸多潜在优势。3D打印建筑金属构件的研究对推动建筑构件智能化、绿色化、自由化的高精度制造具有重要意义。本文采用选区激光熔化技术(Selective Laser Melting,SLM),成功对不锈钢304L管打印成形,对SLM不锈钢304L管的力学性能展开研究,主要包括SLM不锈钢304L成形件材料力学性能及短柱轴压试验研究、有限元模拟及短柱构件国内外设计规范的对比分析。本文先对SLM不锈钢304L管件成形参数进行试验研究,获得了致密度高、成形质量好、力学性能优良的SLM不锈钢304L管件的最佳成形参数。然后对SLM不锈钢304L成形件进行了拉伸试验、硬度测试、残余应力测试和短柱轴压试验,来研究建造方向和退火等因素对材性的影响、硬度与抗拉强度的相关关系、退火前后残余应力水平及短柱构件的力学性能。发现SLM成形件各向异性明显,建造方向、厚度对拉伸性能影响较大。采用ABAQUS有限元分析软件对SLM不锈钢短柱模拟,有限元模拟和试验结果吻合一致,证明了有限元模型的正确性,并进行了有限元扩展模拟,分析了宽厚比、截面形式等对短柱承载力影响。最后本文结合短柱试验和有限元扩大模拟结果,对比国内外不锈钢现行设计规范及计算方法,评估了它们对SLM不锈钢短柱设计的适用性,考虑不锈钢材料应变硬化特征的连续强度法更适合于SLM不锈钢短柱承载力预测,研究为今后3D打印不锈钢建筑构件的设计提供了参考。更多还原

【Abstract】 Based on computer 3D design and the principle of layered stacking manufacturing,3D printing has greatly subverted the traditional metal manufacturing production mode,and can achieve high-precision rapid building of complex metal structures with arbitrary geometric shapes.In the production of architectural steel structure components,compared with traditional steel structure manufacturing technologies such as hot rolling,cold forming,casting and welding,3D metal printing provides great design freedom,at the same time,its process time is shorter,the material strength and the precision of components are higher.While the energy input and the environmental impact are lower.Thus,compared with traditional metal manufacturing technologies,3D printing has many potential advantages.The study of 3D printing architectural metal components is of great importance to push forward the intelligent,green and liberalized high-precision manufacturing in civil engineering.This paper printed stainless steel 304 L tubes by selective lase r melting(SLM).The research mainly focused on the mechanical properties of SLM stainless steel 304 L tubes,the test and finite element analysis on stub columns.Besides,the comparison of design specifications at home and abroad has been conducted.In this paper,the experimental research on best printing parameters of SLM stainless steel 304 L tubes was firstly conducted.The SLM stainless steel304 Ltubes with high density,good forming quality and excellent mechanical properties were obtained.Then,tensile coupon test,hardness test,residual stress test and stub column test were carried out on SLM 304 L stainless steel components.The influence of building directions and annealing on mechanical properties was studied.The correlation between hardness val ue and tensile strength,the residual stress level before and after annealing,and the mechanical properties of stub columns on axil compression has been conducted in detail.It can be found that the anisotropy of SLM forming parts is obvious,and the building direction and thickness have a great influence on the tensile properties.The finite element model of SLM stainless steel stub column was established using the ABAQUS software.The finite element analysis results are in great agreement with the experimental data,the correctness of the finite element model is proved.The finite element extended simulation was carried out to analyze the effects of width-to-thickness ration,cross-section types and strain hardening on bearing capacity of stub columns.Finally,based on the experiments and finite element results of stub columns,a comparison of current stainless steel design specifications and calculation methods at home and abroad was conducted.Their applicability on SLM stainless steel has been evaluated.The continuous strength method considering the strain hardening characteristics of stainless steel is more suitable for predicting the bearing capacity of SLM stainless steel stub columns.The work of this paper provides a certain reference for the design of 3D printing stainless steel architectural components in the future.更多还原