基于TECSA薄膜的螺栓连接CFRP层合板孔边失效模式辨识及损伤定量追踪技术

Quantitatively monitoring hole-edge damage of carbon fiber reinforced plastics (CFRP) bolted joints in the new generation of aircraft is an urgent need. In order to solve this problem, this project proposes a new technique about online mode identification of hole-edge failure and quantitative tracking technique of damage angle, depth and expansion in CFRP laminates of bolted joints based on a novel two-dimensional electromagnetic eddy current sensing array (TECSA) film. Firstly, experimental observation method is proposed to analyze electrical characteristics variations induced by hole-edge compound damage in CFRP laminates, which is utilized to establish the simulation model of CFRP laminates containing hole-edge damage for eddy current analysis and reveal the variation law and internal mechanism of hole-edge eddy current induced by the damage. Secondly, based on the study on the hole-edge eddy current generated/sensed by the exciting/sensing coils, coil topology of the TECSA film in the limited space around the bolt hole edge is optimized to enhance the sensor capacity of synchronously identifying multiple damage parameters. Thirdly, a deep fusion scheme of sensing information acquired by TECSA film is proposed to identify hole-edge failure mode and characterize the angle, depth and expansion of damage in laminates. The research results will provide not only technical support for online monitoring hole-edge failure evolution process in laminates and optimizing layup design of CFRP structures, but also a new monitoring strategy for real-time determining structural integrity and ensuring flight safety of aircraft.

针对新一代飞机螺栓连接碳纤维增强复合材料（CFRP）层合板孔边损伤定量监测的迫切需求，提出一种基于新型二维电磁涡流传感阵列（TECSA）薄膜的螺栓连接CFRP层合板孔边失效模式辨识及复合损伤角度、深度、扩展度在线定量追踪新技术。提出层合板孔边复合损伤引起的电学特性变化的实验观测方法，建立含复合损伤的CFRP层合板孔边涡流分析模型，揭示孔边损伤诱发的孔边涡流变化规律及内在机理。研究激励/传感线圈产生/感知孔边涡流的规律，对螺栓孔边有限空间内的TECSA薄膜线圈阵列进行二维拓扑优化设计，提升传感阵列对损伤多个参数的同步监测能力。提出TECSA薄膜的传感阵列信息深度融合方案，对层合板孔边失效模式进行辨识，对孔边复合损伤的角度、深度、扩展度进行精确定量和表征。研究成果将为在线监测层合板孔边失效演化进程、优化CFRP铺层设计提供技术支持，为实时确定飞机结构完整性、保障飞行安全提供新的监测手段。

螺栓连接是新一代飞行器CFRP主承力结构的主要连接方式，定量监测螺栓连接CFRP层合板孔边损伤对评估飞行器结构完整性、保障飞行器结构飞行安全具有重要的意义。本项目重点从实验和仿真方面研究CFRP层合板孔边损伤引起的孔边涡流变化规律和机理，提出系列化的二维涡流传感阵列（TECSA）薄膜及其传感信息融合新方法，对损伤角度、深度和扩展度进行定量监测。本项目取得了如下主要成果：.（1）构建了含孔CFRP层合板孔边涡流分析的三维有限元模型，分析了嵌入式涡流线圈在含孔CFRP层合板中产生的涡流分布特点，研究发现由于CFRP各方向的导电性能差异较大，其铺层方向决定涡流的主要分布。如损伤影响CFRP纤维主方向，会较大幅度影响涡流流通路径，造成涡流线圈感应电压变化明显。分析结果表明针对CFRP螺栓连接结构孔边损伤定量监测，需要损伤对涡流影响区域化的特点，综合考虑铺层分布和损伤形式设计涡流线圈阵列，对损伤参数进行充分感知和测量。.（2）通过有限元优化设计了沿孔轴向/环向分布或交叉分布的TECSA薄膜，实现孔边损伤角度、深度和扩展程度等参数的定量监测。迭代设计了包含简易二维分布矩形线圈阵列、二维交叉分布矩形线圈阵列、三角形线圈阵列、平行四边形线圈阵列、五边形线圈阵列等一系列涡流线圈拓扑，解决了涡流薄膜尽可能薄、线圈数量尽可能少、损伤监测尽可能不出现盲区等问题。.（3）研究交叉分布的TECSA薄膜对损伤参数的感知特点，提出交叉线圈相减/除的方法反向解析计算损伤角度、单个线圈的变化辨识损伤深度和扩展程度的传感信息融合方法，对孔边损伤参数进行定量辨识。求解出的损伤的角度结合结构受力特点，可以预测螺栓连接结构的失效模式。.（4）还扩展研究了基于涡流/压电耦合传感的螺栓连接结构损伤定量辨识方法、孔边高应变区的新型传感器封装方法、损伤多参数辨识的深度迁移学习方法等，对螺栓连接层合板孔边复合损伤的参数进行高鲁棒性可靠辨识。.本项目发表期刊论文10篇，其中SCI收录9篇，EI收录10篇；授权专利4项。