【摘要】 目的 旨在明确SLM工艺对TC4钛合金力学性能的影响，建立适用于该材料的动态本构关系，并评估其加筋板结构在破片冲击下的防护性能。方法 SLM增材制造TC4钛合金拉伸与压缩试样，通过准静态拉伸测试和分离式霍普金森压杆实验，获取其静、动态力学性能数据，并拟合Johnson-Cook本构模型参数。将所得本构模型应用于有限元仿真，分析加筋板结构受破片撞击的损伤行为。结果 实验结果表明，SLM工艺制备的TC4钛合金抗拉强度可达1 040 MPa，优于传统锻铸材料，并且表现出应变率强化效应。仿真结果显示，破片撞击下加筋板的破坏主要集中于加强筋与基板衔接处，呈现明显的剪切断裂；同时，靶板大变形引发的拉伸断裂也是重要失效模式。加强筋在冲击过程中有效耗散了破片动能，但其衔接处的应力集中与潜在打印缺陷导致结构易在该处发生毁伤。结论 SLM技术可提升TC4钛合金的力学性能，拟合的Johnson-Cook本构模型能有效用于其动态冲击仿真。加筋板结构在破片撞击下防护性能显著，但加强筋与基板衔接处因应力集中和制造缺陷成为薄弱环节。本研究为3D打印钛合金加筋板在防护工程中的应用提供了理论依据与设计参考。更多还原

【Abstract】 The work aims to clarify the effect of the SLM process on the mechanical properties of TC4 titanium alloy, establish a dynamic constitutive model suitable for this material, and evaluate the protective performance of its stiffened plate structure under fragment impact. Tensile and compression specimens of TC4 titanium alloy were additively manufactured via SLM. Quasi-static tensile tests and split Hopkinson pressure bar experiments were conducted to obtain static and dynamic mechanical property data, and the parameters of the Johnson-Cook constitutive model were fitted. The obtained constitutive model was then applied in finite element simulations to analyze the damage behavior of the stiffened plate structure under fragment impact. Experimental results showed that the tensile strength of TC4 titanium alloy prepared by SLM reached 1 040 MPa, surpassing that of traditional wrought/cast materials, and it exhibited a strain rate strengthening effect. Simulation results indicated that the damage to the stiffened plate under fragment impact was primarily concentrated at the junction between the stiffeners and the base plate, exhibiting obvious shear fracture. Simultaneously, tensile fracture caused by significant deformation of the target plate was also an important failure mode. The stiffeners effectively dissipated the kinetic energy of the fragment during impact. However, stress concentration at their junctions and potential printing defects made the structure prone to damage in these areas. SLM technology can enhance the mechanical properties of TC4 titanium alloy, and the fitted Johnson-Cook constitutive model can be effectively used for its dynamic impact simulation. The stiffened plate structure demonstrates significant protective performance under fragment impact, but the junction between the stiffeners and the base plate becomes weak points due to stress concentration and manufacturing defects. This study provides a theoretical basis and design reference for the application of 3D-printed titanium alloy stiffened plates in protective engineering.更多还原