金属增材制造中反复熔凝造成的残余应力，为何会引发变形甚至开裂？
Why do residual stresses from repeated melting and solidification in metal additive manufacturing cause distortion or even cracking?
每层快速熔化的金属冷却收缩时受到已凝固层的约束，产生拉应力，逐层累积形成宏观残余应力场。当应力超过材料的屈服强度便发生翘曲变形，超过断裂韧性则在应力集中处萌生裂纹，尤其在高强度铝合金和钛合金中常见，需靠预热、扫描策略或热处理缓解。
Each rapidly melted layer shrinks on cooling but is constrained by the already solidified layers below, generating tensile stress that accumulates into a macroscopic residual stress field. When it exceeds yield strength the part warps, and when it exceeds fracture toughness cracks initiate at stress concentrations—common in high-strength aluminum and titanium alloys—requiring preheating, scan strategies, or heat treatment to mitigate.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-11-04
来源 · Source
Li 等,《Efficient predictive model of part distortion and residual stress in selective laser melting》,Additive Manufacturing,2017 (DOI: 10.1016/j.addma.2017.08.014)
Li et al., 'Efficient predictive model of part distortion and residual stress in selective laser melting', Additive Manufacturing, 2017, DOI: 10.1016/j.addma.2017.08.014
独立核验依据 · Independent verification: 核验依据 1 Crossref DOI 10.1016/j.addma.2017.08.014
#残余应力 #热循环 #翘曲 #开裂
电弧增材制造（WAAM）相比粉末床熔融，在大尺寸金属构件上有哪些优势与局限？
Compared with powder-bed fusion, what are the advantages and limitations of wire arc additive manufacturing (WAAM) for large metal structures?
WAAM 以焊丝为材料、电弧为热源，沉积速率可达千克级每小时，非常适合米级大型构件且材料利用率高、成本低。但电弧热输入大导致热累积明显、尺寸精度与表面质量较差，通常需要后续机加工，且晶粒粗大、各向异性更强，需通过工艺与热处理调控性能。
WAAM uses welding wire and an electric arc, achieving deposition rates on the order of kilograms per hour, ideal for meter-scale parts with high material use and low cost. But the large heat input causes significant thermal accumulation, poorer dimensional accuracy and surface finish that often require machining, plus coarser grains and stronger anisotropy that must be controlled by process and heat treatment.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 来源待核验 · Source pending review
来源 · Source
出处备注：此条未指向带版次的可引用著作（通识性内容、机构文件或未展开的英文书名），本库不提供独立书目出处；如需精确引用，需由编辑补全具体篇目与版次。
Elsevier（CIRP Annals 制造技术）
Elsevier (CIRP Annals - Manufacturing Technology)
#电弧增材 #大尺寸构件 #沉积速率 #各向异性
拓扑优化在设计轻量化增材制造零件时，如何与制造约束耦合以避免不可制造的结构？
In designing lightweight additively manufactured parts, how is topology optimization coupled with manufacturing constraints to avoid unmanufacturable geometries?
标准拓扑优化只追求刚度/重量最优，常生成极薄悬垂与复杂内腔，难以实际打印。工程做法是在优化目标中嵌入制造约束（如最小尺寸、自支撑角度、可移除支撑限制），或用基于机器学习的生成式设计，使所得构型同时满足力学最优与打印可行性。
Standard topology optimization only seeks stiffness-to-weight optimality and often yields ultra-thin overhangs and complex cavities that are hard to print. Engineering practice embeds manufacturing constraints (minimum member size, self-supporting angles, support-removal limits) into the objective, or uses generative design with learned rules, so the result is both mechanically optimal and printable.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-11-04
来源 · Source
Rosnitschek, Baumann, Orgeldinger, Alber-Laukant,《Manufacturing Constraints in Topology Optimization for the Direct Manufacturing of Extrusion-Based Additively Manufactured Parts》,Designs,2023 (DOI: 10.3390/designs7010008)
Rosnitschek, Baumann, Orgeldinger, Alber-Laukant, 'Manufacturing Constraints in Topology Optimization for the Direct Manufacturing of Extrusion-Based Additively Manufactured Parts', Designs, 2023, DOI: 10.3390/designs7010008
独立核验依据 · Independent verification: 核验依据 1 Crossref DOI 10.3390/designs7010008
#拓扑优化 #轻量化 #制造约束 #生成式设计
工程中的数字孪生与普通的计算机仿真模型最关键的区别是什么？
What is the key difference between an engineering digital twin and an ordinary computer simulation model?
普通仿真模型通常是离线的、基于假设的静态模型；数字孪生则与实际物理对象通过实时传感数据持续连接，能随对象状态变化动态更新并用于预测与优化。它强调实时数据闭环和全生命周期同步，而不只是一次性分析。
An ordinary simulation is typically an offline, assumption-based static model, whereas a digital twin is continuously linked to its physical counterpart through real-time sensor data, updating dynamically to predict and optimize. It emphasizes a real-time data feedback loop and whole-lifecycle synchronization rather than one-off analysis.
难度 进阶 · 适合 大众
CC BY 4.0 · 来源待核验 · Source pending review
来源 · Source
出处备注：著录含书名，但缺版次 / 出版社 / 年份中的一部分，需编辑补全后才能做独立比对。
Grieves，《数字孪生：通过虚拟工厂复制实现制造卓越》（2014）
Grieves, 'Digital Twin: Manufacturing Excellence through Virtual Factory Replication' (2014)
#数字孪生 #实时数据 #仿真 #全生命周期
选区激光熔化（SLM）制造金属零件时，哪些工艺参数最显著影响最终致密度？
Which process parameters most strongly affect the final density of metal parts made by selective laser melting (SLM)?
激光功率、扫描速度、扫描间距和层厚共同决定了单位面积能量输入（线能量/体能量）。能量过低会产生未熔合孔洞，过高则引发汽化与飞溅；合理匹配这些参数通常可获得 99% 以上的相对致密度，是 SLM 工艺优化的核心。
Laser power, scan speed, hatch spacing, and layer thickness together determine the energy input per unit area (line or volumetric energy density). Too little energy causes lack-of-fusion pores, while too much causes vaporization and spatters; well-matched parameters typically yield above 99% relative density, which is the core of SLM process optimization.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-11-04
来源 · Source
DebRoy、Wei、Zuback 与 Mukherjee,《Additive manufacturing of metallic components – Process, structure and properties》,Progress in Materials Science,2018 (DOI: 10.1016/j.pmatsci.2017.10.001)
DebRoy, Wei, Zuback & Mukherjee, 'Additive manufacturing of metallic components – Process, structure and properties', Progress in Materials Science, 2018, DOI: 10.1016/j.pmatsci.2017.10.001
独立核验依据 · Independent verification: 核验依据 1 Crossref DOI 10.1016/j.pmatsci.2017.10.001
#选区激光熔化 #致密度 #工艺参数 #金属 3D 打印
面向增材制造的设计（DfAM）相比传统设计主要改变了哪些思路？
How does design for additive manufacturing (DfAM) mainly change thinking compared with conventional design?
传统设计受限于减材与铸造的可加工性，常需拆分多个零件再装配；DfAM 利用增材可成型任意复杂几何的特点，鼓励零件一体化、功能集成与随形冷却流道等。设计师还需考虑支撑结构最少化、悬垂角度和热变形，使设计同时从性能与可制造性出发。
Conventional design is constrained by machining and casting, often requiring parts to be split and assembled; DfAM exploits arbitrary complexity to encourage part consolidation, functional integration, and conformal cooling channels. Designers also minimize supports, respect overhang angles, and account for thermal distortion, optimizing for both performance and manufacturability.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 来源待核验 · Source pending review
来源 · Source
出处备注：著录仅给书名，无版次与年份；同一书名常对应多个版次，不臆测具体版本。
Gibson、Rosen & Stucker，《增材制造技术：从快速原型到直接数字化制造》（第2版）
Gibson, Rosen & Stucker, 'Additive Manufacturing Technologies: Rapid Prototyping to Direct Digital Manufacturing' (2nd ed.)
#DfAM #零件一体化 #功能集成 #随形冷却
熔融沉积成型（FDM）打印零件时，为什么常需要设置打印填充率？
Why is infill density commonly specified when printing parts by fused deposition modeling (FDM)?
FDM 通过逐层挤出热塑性丝材成型，零件内部通常不需要完全实心。设置填充率可在保证强度与刚度的前提下大幅减少材料用量和打印时间，外壳承担主要载荷，内部网格仅提供支撑与抗弯刚度。
FDM builds parts by extruding thermoplastic filament layer by layer, and the interior need not be fully solid. Setting an infill percentage greatly reduces material use and print time while keeping strength and stiffness, since the outer shell carries most load and the internal lattice mainly provides support and bending stiffness.
难度 进阶 · 适合 大众
CC BY 4.0 · 来源待核验 · Source pending review
来源 · Source
出处备注：此条未指向带版次的可引用著作（通识性内容、机构文件或未展开的英文书名），本库不提供独立书目出处；如需精确引用，需由编辑补全具体篇目与版次。
ASTM F42 / ISO 17296（增材制造术语与工艺）
ASTM F42 / ISO 17296 (additive manufacturing terminology)
#熔融沉积成型 #填充率 #热塑性 #3D 打印
增材制造中的点阵（晶格）结构常用于实现什么工程目标？
What engineering goals are lattice structures in additive manufacturing commonly used to achieve?
通过体心立方、gyroid 等周期性点阵，可在保持一定刚度和比强度的同时大幅降低零件质量，并实现能量吸收、隔热或多孔植入等功能。这类复杂内部几何传统减材工艺难以加工，而对增材制造却几乎无额外成本，因此被广泛用于航空航天与医疗部件。
Periodic lattices such as body-centered cubic or gyroid can sharply reduce mass while retaining stiffness and specific strength, and also provide energy absorption, thermal insulation, or porous implant functions. Such complex internal geometry is hard to machine by subtraction but nearly free with additive manufacturing, so it is widely used in aerospace and medical parts.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 来源待核验 · Source pending review
来源 · Source
出处备注：著录仅给书名，无版次与年份；同一书名常对应多个版次，不臆测具体版本。
《材料科学》（多孔与点阵材料）
Materials Science (porous and lattice materials)
#点阵结构 #轻量化 #能量吸收 #比强度