Compressive characteristics of radially graded porosity scaffolds architectured with minimal surfaces
Compressive characteristics of radially graded porosity scaffolds architectured with minimal surfaces
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DOI：
10.1016/j.msec.2018.06.051
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发表时间：
2018-11-01
影响因子：
7.9
通讯作者：
Montazerian, H.
中科院分区：
文献类型：
--
作者：
Afshar, M.;Anaraki, A. Pourkamali;Montazerian, H.
具有梯度孔特征的支架受到了极大的关注，因为它们可以更好地模拟天然组织的结构并同时满足生物学和机械要求。在本研究中，孔隙率的几何形状和孔隙率梯度图案的变形机制和压缩力学性能的结构的影响进行了研究的背景下，拉伸（I-WP和P表面）与弯曲为主（D表面）三重周期性最小表面（TPMS）为基础的架构。不同的梯度模式被发现显着改变变形机制。径向梯度模式（垂直于加载方向）提供更高的变形能力，而纵向梯度支架遭受低失效应变。在拉伸为主的结构中，由于材料在压缩下的横向膨胀，垂直裂纹在压缩下扩展。然而，弯曲主导结构中的变形伴随着由于支柱的剪切而导致的进行性塌陷。一般来说，拉伸主导的结构显示出更高的机械性能，并在机械载荷下提供更高的效率。有限元模拟还表现出预测变形以及机械响应（特别是弹性性能）的高能力，并且可以用作设计多功能梯度多孔支架的工具。
Scaffolds with gradient pore characteristics have received a great deal of attention as they can better mimic the structure of the native tissues and concurrently meet both biological and mechanical requirements. In the present study, the effects of porosity geometry and porosity gradient patterns on the deformation mechanism and compressive mechanical properties of the structures were investigated in the context of stretching (I-WP and P surfaces) versus bending dominated (D surface) triply periodic minimal surface (TPMS) based architectures. Different gradient patterns were found to significantly alter the deformation mechanism. Radial gradient patterns (perpendicular to loading direction) provide higher deformability while longitudinally graded scaffolds suffer from low failure strain. In the stretching dominated architectures vertical cracks propagated under compression due to the materials transverse expansion under compression. Deformations in the bending dominated architectures, however, were accompanied by a progressive collapse owing to the shearing of the struts. In general, stretching dominated structures showed the higher mechanical properties and provided more efficiency under mechanical loads. Finite Element simulations also demonstrated a high capability for predicting the deformation as well as mechanical responses (especially for elastic properties) and can be used as a tool for designing multifunctional gradient porous scaffolds.