Monitoring and defect detection in production and maintenance of thick composite componentes

为了充分发挥纤维增强塑料的潜力，了解其失效机理和缺陷的影响是不可避免的，本研究项目的重点之一是采用高压树脂传递模塑（HP-RTM）技术生产厚玻璃纤维增强塑料层压板。另一个重点将是调查的层压板厚度和机械性能的依赖性。IKT（斯图加特大学）的研究活动将是从生产到失效的厚层压板的无损检测和可检测性。IKT的一个目标是检测（HP-RTM）过程中的树脂流动前沿。层压材料的厚度将在4到10毫米之间。将使用无损相控阵矩阵超声检测方法。特别是改变超声信号的反射的影响将被强调。所有的准备工作和结果都将与ILK（德累斯顿工业大学）合作进行评估。IKT的另一个目标是无损研究局部纤维波度和整体层波度对厚层压板机械性能的影响。空气耦合超声和超声矩阵相控阵将被用作无损检测方法，以检测裂纹和分层等缺陷。根据层合板的缺陷程度，对损伤程度进行监测。此外，利用差分飞行时间法对层合板刚度进行的无损检测数据将为IPC（Hamburg University of Technology）进行的残余应力模拟奠定基础。IKT的进一步目标是研究层合板厚度对强度和疲劳行为的影响。无损检测方法空气耦合超声和超声矩阵相控阵将再次使用，而静态和动态负载的机械测试。结果将构成IFL（布伦瑞克理工大学）进行模拟的基础，并与声发射测试相匹配。

In order to exploit the full potential of fiber reinforced plastics, it is inevitable to understand their failure mechanisms and the effects of defects.One focus of this research project will be the production of thick glass fiber reinforced plastic laminates with high pressure resin transfer molding (HP-RTM). Another focus will be investigations of the dependence of laminate thickness and mechanical properties. Research activities of the IKT (University of Stuttgart) will be the nondestructive test- and detectability of thick laminates from production to failure.One objective of the IKT is the detection of the resin flow front during (HP-RTM). The laminate thickness will be between four and ten millimeters. The nondestructive Phased Array Matrix Ultrasonic Testing method will be used. Especially the influence of changing reflections of the ultrasound signal will be emphasized. All preparations and results will be evaluated in cooperation with the ILK (Dresden University of Technology).Also an objective of the IKT is non-destructive investigation of the influence of local fiber waviness and global layer waviness on the mechanical properties of thick laminates. Air-coupled Ultrasound and Ultrasound Matrix Phased Array will be utilized as nondestructive testing methods to detect defects like cracks and delaminations. The damage extend will be monitored depending on the imperfection of the laminate. Additionally, nondestructive testing data of the laminate stiffness using the Differential Time of Flight method will establish a basis for simulation of residual stresses conducted by the IPC (Hamburg University of Technology).A further objective of the IKT is investigation of the influence of laminate thickness on the strength and fatigue behavior. Nondestructive testing methods Air-coupled Ultrasound and Ultrasound Matrix Phased Array will again be used, whilst mechanical testing with static and dynamic load. Results will form the basis for simulations performed by the IFL (Braunschweig University of Technology) and are matched to Acousting Emission testing.