The current study is proposing a design envelope for porous Ti-6Al-4V alloy femoral stems to survive under fatigue loads. Numerical computational analysis of these stems with a body-centered-cube (BCC) structure is conducted in ABAQUS. Femoral stems without shell and with various outer dense shell thicknesses (0.5, 1.0, 1.5, and 2 mm) and inner cores (porosities of 90, 77, 63, 47, 30, and 18%) are analyzed. A design space (envelope) is derived by using stem stiffnesses close to that of the femur bone, maximum fatigue stresses of 0.3σ_ys in the porous part, and endurance limits of the dense part of the stems. The Soderberg approach is successfully employed to compute the factor of safety N_f > 1.1. Fully porous stems without dense shells are concluded to fail under fatigue load. It is thus safe to use the porous stems with a shell thickness of 1.5 and 2 mm for all porosities (18–90%), 1 mm shell with 18 and 30% porosities, and 0.5 mm shell with 18% porosity. The reduction in stress shielding was achieved by 28%. Porous stems incorporated BCC structures with dense shells and beads were successfully printed.

目前的研究提出了一种设计包络线，使多孔 Ti-6Al-4V 合金股骨柄能够承受疲劳载荷。这些具有体心立方 (BCC) 结构的茎的数值计算分析在 ABAQUS 中进行。分析了没有壳和具有各种致密壳厚度（0.5、1.0、1.5 和 2 毫米）和内核（孔隙率为 90%、77%、63%、47%、30% 和 18%）的股骨柄。设计空间（包络线）是通过使用接近股骨的杆刚度、多孔部分的最大疲劳应力 0.3σ _ys以及杆的致密部分的耐久性极限推导出来的。Soderberg 方法已成功用于计算安全系数N _f> 1.1. 没有致密壳的全多孔茎被认为在疲劳载荷下会失效。因此，对于所有孔隙率 (18–90%) 使用壳厚度为 1.5 和 2 mm 的多孔茎是安全的，对于孔隙率 18% 和 30% 使用 1 mm 壳，以及具有 18% 孔隙率的 0.5 mm 壳。应力屏蔽减少了 28%。多孔茎结合了 BCC 结构与致密的壳和珠子被成功打印。