考虑主动控制的空气支承式涂层织物膜结构多场耦合分析与设计方法

Air-supported membrane structure is a particular kind of active control structure, which is mostly built with coated fabric architectural membrane, and tear resistance is one main issues of design. However, the two basic problems have not been researched well; this results in design issues of equipment, control and membrane structure. .Air-supported membrane structure is assumed to be composed of inherent four components, inner air field, large deformed coated-fabric membrane, external load or wind field, active control. Based on fluid structure interaction theory, the air field in membrane and outside is described by Navier-Stokes equation with time-averaging Reynolds and k-ε turbulence model. Partition coupling method is used for numerical efficiency due to large scale. Finally by introducing into feed-back and forward-back control, the unified dynamic control model is developed with mathematic model of four components and its interaction, as well as numerical simulation method. The dynamic control behavior would be investigated thoroughly. .The Proportional Integral Differential (PID) control based on Back Propagation neural network is adopted to establish the real-time control model due to nonlinear deep-coupling and large time-delay, the field dynamic monitor system is developed creatively, and the field dynamic monitor experiments will be carried out for the particular air-supported membrane structure, as well as aero-elastic dynamic behavior analysis. .The biaxial tensile experimental technique which accurately reflects the mechanical performance of pneumatic stressed membrane structure is employed for the coated-fabric tests. Through central slit crack and strength tests, the tear propagation and strength criteria are formulated with the damage theory and strength criteria of orthotropic composite material, the nonlinear mechanical behavior and constitutive model is investigated comprehensively. .On the basis of theory research, the software and monitor control system are developed accordingly, and then applied to the practical engineering projects, the work would promote development of design technology and analysis theory of the inflated-membrane structures.

空气支承式膜结构是主动控制结构，其主体涂层织物的抗撕裂是设计核心，而这两点基础研究尚少，由此导致设备、控制及结构设计问题。项目考虑膜内空气流场、大变形膜结构、外载荷和主动控制四要素模型及相互作用模型，以流固耦合理论为基础，采用Reynolds时均N-S方程和k-ε模型描述流场及弱耦合分区法，引入控制模型，建立空气支承式膜结构动力学控制模型和数值模拟方法，研究动力学控制行为机理；采用基于BP神经网络的PID控制方法建立气膜实时控制模型，研制动力学控制实时监测系统，进行实时监测试验和动力学分析，研究实时动力学控制行为特征；采用准确反映膜结构实际二维受力特征的双轴拉伸试验技术，通过双轴拉伸中心撕裂和强度试验，基于复合材料损伤和强度理论，建立气膜涂层织物膜的撕裂强度和拉伸强度准则，研究非线性力学行为和力学模型。针对所研究理论方法开发分析软件和监测控制系统，将理论与工程应用结合，促进充气膜结构发展。

空气支承式膜结构是主动控制结构，其主体涂层织物的抗撕裂是设计核心，而这两点基础研究尚少，由此导致设备、控制及结构设计问题。.本项目发明了大跨度膜结构健康监测系统、织物膜材测试设备、剪切、拉剪、双轴拉伸强度测试方法，建立了从材料到结构的测试技术体系，进行了实际气承式膜结构工程的监测、系列织物膜材的参数试验和力学行为研究，从而使大型膜结构的科学设计具备了扎实的技术和试验基础。.通过监测系统，首次获得了利奇马台风过境大跨气承式膜结构的环境和结构响应参数，包括风场、结构表面风压、变形、加速度、气压等，揭示了大跨气承式膜结构的风致动力特性，为准确认识其物理、力学机理奠定了试验基础。风场呈非高斯随机特征、空间相关性，结构低频0.28Hz，空气附加质量影响有限，在高压模式下内压波动较小（<15Pa）。.分别采用基于时域随机振动分析和流固耦合分析建立气承式膜结构数值模拟方法。基于Reynolds时均N-S方程和k-ξ模型对结构的平均风压分布进行数值模拟，采用有限体积法和SIMPLE压力校正算法来实现非线性离散化方程的解耦和迭代求解。.以封闭三角形或四边形的索网为膜单元边界，构建膜单元，以保证索、膜节点的几何协调性。考虑实际索网及分片，构建精细的大跨气承式膜结构模型。.经研究，内流场呈稳态特性，其动态对结构整体影响较小，可假设为内压载荷，同时，基于工业可行的控制策略，采用弱耦合进行气承式膜结构流固耦合分析。.基于柔性织物膜材物理特性的认识，提出拉剪耦合本构模型，即剪切模量与拉力正相关；并基于织物膜双轴拉伸响应面，构建织物膜材正交异性非线性力学模型。提出拉剪耦合强度准则，可通过双轴试验标定模型参数。力学模型准确预测了球形囊体充气爆破位置、安全系数，解决了工业领域长期存在的瓶颈问题。.研究成果为织物膜结构强度设计、安全性分析提供了更为科学的方法，可应用于大型气承式膜结构，以及飞艇等织物结构。