An Integrated Micromechanics Approach to Physics-Based Modeling of Deformation and Failure of Superelastic Materials

基于物理建模的超弹性材料变形与破坏的集成微力学方法[j]。Papadopoulos和R.O. ritchiei提出的工作目标是建立一个综合的实验，理论和计算描述的变形，断裂和多晶超弹性/形状记忆合金的循环疲劳行为。智力优势：提出的工作旨在描述复杂纹理材料的力学行为，这些材料经历了一系列固-固相变，这对其多轴应力-应变响应和疲劳特性有重要影响。这项研究的智力价值源于它所解决的具有挑战性的问题，以及所提出的方法的综合性质（实验、理论、计算）。更广泛的影响：超弹性合金的使用正在经历爆炸式的增长，主要是在生物医学设备中，但也在许多其他民用和军事应用中。举例来说，2003年仅在美国，心血管支架行业每年的产值估计就达到50亿美元，而超弹性ni - ti合金正迅速成为这些支架的主要材料。同时，这种合金的力学响应存在很大的不确定性，特别是在多轴载荷和循环疲劳作用下。提出的研究旨在解决这些不确定性，从而有助于在工程实践中更安全、更合理地使用这些材料。

An Integrated Micromechanics Approach to Physics-basedModeling of Deformation and Failure of Superelastic MaterialsP. Papadopoulos and R.O. RitchieThe objective of the proposed work is to develop an integrated experimental,theoretical and computational description of the deformation, fracture and cyclic fatigue behavior of polycrystalline superelastic/shape-memory alloys. Intellectual Merit: The proposed work seeks to characterize the mechanical behavior of a complextextured material that undergoes a series of solid-solid phase transitions, which crucially affect its multiaxial stress-strain response and its fatigue characteristics. The intellectual merit of the research stems from the challenging questions that it addresses and from the integrated nature(experiments, theory, computing) of the proposed methodologies. Broader Impact: Superelastic alloys are experiencing an explosive growth in use, mostly inbiomedical devices, but also in a number of other civilian and militaryapplications. As an example, the cardiovascular stent industry in 2003 is estimated at 5 billion dollars per year in the US alone and superelasticNi-Ti alloys are fast becoming the principal material for these stents. At the same time, there exist significant uncertainties regarding the mechanical response of such alloys, especially under multiaxial loading and cyclic fatigue. The proposed research intends to address these uncertainties, thus contributing to the safer and more rational use of these materials in engineering practice.