固体力学跨尺度计算若干问题研究  

Several problem studies in solid mechanics by spanning the scale computation analysis

作　　者：庄茁[1] 严子铭 姚凯丽 崔一南[1] 柳占立[1] ZHUANG Zhuo;YAN Zi-ming;YAO Kai-li;CUI Yi-nan;LIU Zhan-li(School of Aerospace Engineering,Tsinghua University,Beijing 100084,China)

机构地区：[1]清华大学航天航空学院,北京100084

出　　处：《计算力学学报》2024年第1期40-46,共7页Chinese Journal of Computational Mechanics

基　　金：国家自然科学基金(11132006,10772096,11972210,12272204)资助项目.

摘　　要：本文展示了固体力学领域跨尺度计算的若干问题和研究概况。(1)建立位错动力学与有限元耦合DDD-FEM的计算模型,实现了能够基于纳米尺度离散位错运动机制计算分析连续介质有限变形晶体塑性问题,提出微纳尺度(200 nm~10μm)晶体塑性流动应力解析公式,结合试验数据揭示了在无应变梯度下强度和变形的尺寸效应;(2)建立具有微相分离结构的纳米尺度粗粒化分子动力学模型CG-MD,计算获得聚脲材料在时域和频域下的存储模量和损耗模量,通过动态加载分析的DMA试验和超声波试验的数据验证,解决了连续介质尺度下微相分离高分子共聚物的设计难题;(3)通过数据驱动关联高分辨率的微米尺度CT影像和临床低分辨率的毫米尺度CT影像的特征值,建立了围关节松质骨小梁的等效模量和结构张量,为骨组织增材制造点阵结构设计和实现个性化骨缺损重建奠定了基础。This paper presents several problem studies in solid mechanics area by spanning the scale computation analysis.(1)The calculation model of coupling discrete dislocation dynamics and the finite element method(DDD-FEM)is proposed,which realizes the study for finite deformation crystal plasticity based on dislocation mechanism,and establishes the theory of plastic flow stress at micro-scale and nano-scale(200 nm~10μm),and combines with test data to verify the size effects of strength and deformation without strain gradient.(2)The storage modulus and loss modulus of micro-scale polyurea in time domain and frequency domain are obtained by using the nano-scale coarse-grained molecular dynamics model(CG-MD).The design problem of microphase separation polymer copolymers is solved by dynamic loading analysis and ultrasonic test data verification.(3)Through data-driven identification of the characteristic values of high-resolution micro-scale CT images and clinical low-resolution millimeter-scale CT images,the equivalent modulus and structural tensor of articular cancellous bone trabeculae is established,which lays the foundation for the bone tissue structure additive manufacturing lattice design and personalized bone defect reconstruction.

关 键 词：计算固体力学 跨尺度 微纳米晶体塑性流动应力 粗粒化分子动力学 数据驱动骨缺损重建 

分 类 号：O302[理学—力学]