Biological and mechanical functions are sometimes two conflicting characteristics in bone tissue scaffolds, which necessitates a trade-off between these two properties in load-bearing applications. In this article, a systematic computational analysis was performed to investigate the effects of controllable fabrication factors (e.g. Design for Additive Manufacturing (DAM) Parameter) on compressive strength and permeability of ceramic scaffolds fabricated by robocasting technique, followed by a study on multiobjective optimization to determine the optimal structural parameters. To evaluate the compressive strength of scaffolds, the eXtended Finite Element Method (XFEM) was adopted to model fracture behavior in the scaffolds. Computational Fluid Dynamics (CFD) simulations were also conducted to analyze the permeability of the scaffold structures to quantify their biotransport capacity. Furthermore, experimental compression tests and fluid flow tests were conducted for some representative scaffolds to demonstrate the effectiveness of both XFEM and CFD simulations. The computational results indicated that the anisotropic degree of permeability could be controlled by adjusting particular geometric parameters during design and fabrication process, thereby enabling desirable directional permeability in each of longitudinal and transverse directions. Moreover, the XFEM results demonstrated that compressive strength of the scaffolds can be improved by at least 70 % while the porosity is kept unchanged, which is of considerable implication to design of robocast ceramic scaffolds for weight-bearing tissue engineering.

在骨骼组织支架中，生物学和机械功能有时是两个相互矛盾的特性，因此在承重应用中必须在这两个特性之间进行权衡。在本文中，进行了系统的计算分析，以研究可控的制造因素（例如，增材制造设计（DAM）参数）对通过机器人浇铸技术制造的陶瓷支架的抗压强度和渗透性的影响，然后进行了多目标优化研究确定最佳结构参数。为了评估支架的抗压强度，采用扩展有限元法（XFEM）对支架的断裂行为进行建模。还进行了计算流体动力学（CFD）模拟，以分析支架结构的渗透性以量化其生物转运能力。此外，还对一些代表性的脚手架进行了压缩试验和流体流动试验，以证明XFEM和CFD模拟的有效性。计算结果表明，可以通过在设计和制造过程中调整特定的几何参数来控制渗透率的各向异性，从而在纵向和横向方向上实现理想的方向渗透率。此外，XFEM结果表明，在保持孔隙率不变的情况下，可以将支架的抗压强度提高至少70％，