To identify generalised principles for structural topology optimisation with respect to damage tolerance across multiple scales

确定关于跨多个尺度的损伤容限的结构拓扑优化的通用原则

• 批准号: 2281132
• 金额: --
• 依托单位: Newcastle University
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2019
• 资助国家: 英国
• 起止时间: 2019 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2281132
• 关键词: identify; generalised; principles; structural; topology

Objectives* Generate three discretised structural geometries: cubic lattice, sodalite cage and tetrahedral truss, at different length scales and with a range of geometric stochasticity and structural hierarchy* Measure structural response with a non-linear dynamic discrete element simulation of structural collapse* Verify simulations with physical testing on prototype 3D printed elements* Optimise topologies algorithmically with respect to damage tolerance* Form a set of principles for an a priori approach to robustness orientated design. Synthesising results from optimisation and effects of topological variationThis is an endeavour towards furthering robustness-oriented preliminary design. Meaningful contributions will be made towards the process of modelling and indexing progressive collapse resistance. With the state-of-the-art modelling methodologies developed and verified over the course of the project proving useful in determining optimally robust topologies.1 Generate structural geometriesI will develop a Matlab script to generate topological information. continues geometries will be represented in the form of particle and connectivity data. Defining the locations of massive spherical discrete elements and force potentials connecting them.2 Discrete element simulation of structural collapseDEM was chosen in order to facilitate fracture and rupture of members, difficult to implement in a finite element approach. I will undertake simulation in the software LAMMPS. Conventionally used for materials modelling at the nano and micro scales, modified to include particle bonds that can capture structural responses at larger scales. Combining Hertzian contact forces with new bond interactions that will include local plasticity. At this stage the simulations will be element scale simulating response in compression and bending. 3 Verify simulations with 3D printed elementsOnce results for the performance of the various structures are acquired it will be important to verify the modelling process and validate the results obtained before the next round of simulation can begin.Prototype geometries will be printed out. In the lab it will then be possible to test their mechanical response to conditions representative of those applied during simulation. Comparison of simulated verses physical response will be made in terms of deflections, ultimate strength, and fracture propagation. If necessary, the model will be refined until a high level of correspondence exists between the two in all cases.A workflow from geometry generation, to simulation, to manufacture will have been developed. To serve as a base for the further investigations.4 Topological optimisationI will conduct an extensive exploration into robustness-oriented design principles. The second stage of the simulation involves investigating the links between geometric parameters and damage tolerance. Simulations will be run with respect to specific scenarios of notional element loss simulating likely damage events.This optimisation process will search for structural configurations optimally resistant to progressive collapse and catastrophic failure through an integrated algorithmic process linking Matlab to LAMMPS in Model centre. Allowing for the programming of a genetic optimisation loop to explore the effects of stochasticity and long-range connections on robustness.5 A-priori robustness-oriented design principlesFrom the optimisation process will be obtained simulations of failure progression of both optimised and unoptimized structural forms as well as mechanisms of failure and measures of damage tolerance quantified in the form of a robustness index.Compiling and analysis of this data will be undertaken to derive the kinds of robustness-oriented design procedures described in the project aim.

*生成三个离散的几何结构：立方晶格、硅笼和四面体桁架，在不同的长度尺度和几何随机性和结构层次的范围内*测量结构响应与非线性动态离散元模拟结构崩溃*验证模拟与原型3D打印元件的物理测试*优化拓扑算法相对于损伤容限*形成一套原则的先验方法鲁棒性为导向的设计。综合优化的结果和拓扑变化的影响这是进一步面向鲁棒性的初步设计的努力。将对模拟和索引渐进倒塌抗力的过程作出有意义的贡献。在项目过程中开发和验证了最先进的建模方法，证明在确定最佳鲁棒拓扑方面是有用的生成结构几何我将开发一个Matlab脚本来生成拓扑信息。连续几何将以粒子和连通性数据的形式表示。定义大量球面离散单元的位置和连接它们的力势结构崩塌的离散元模拟选择dem是为了方便构件断裂和破裂，而有限元方法难以实现。我将在LAMMPS软件中进行模拟。通常用于纳米和微观尺度的材料建模，修改后包括粒子键，可以捕获更大尺度的结构响应。结合赫兹接触力与新的键相互作用，将包括局部塑性。在这个阶段，模拟将是单元尺度模拟压缩和弯曲的响应。3用3D打印元素验证模拟一旦获得了各种结构的性能结果，在开始下一轮模拟之前验证建模过程和验证获得的结果将是非常重要的。原型几何图形将被打印出来。在实验室中，将有可能测试它们对模拟中应用的条件的机械响应。将在挠度、极限强度和裂缝扩展方面对模拟响应与物理响应进行比较。如果有必要，将对模型进行改进，直到在所有情况下两者之间都存在高度的对应关系。从几何图形生成到仿真再到制造的工作流程将被开发出来。作为进一步调查的基地拓扑优化我将对面向健壮性的设计原则进行广泛的探索。模拟的第二阶段涉及研究几何参数与损伤容限之间的联系。模拟将针对特定场景的概念元素损失模拟可能的损害事件。该优化过程将通过集成算法过程将Matlab与模型中心的LAMMPS连接起来，寻找最能抵抗渐进崩溃和灾难性失败的结构配置。允许对遗传优化回路进行编程，以探索随机性和远程连接对鲁棒性的影响从优化过程中，将获得优化和非优化结构形式的失效进展模拟，以及以鲁棒性指数形式量化的失效机制和损伤容限措施。将对这些数据进行汇编和分析，以得出项目目标中描述的各种面向鲁棒性的设计程序。