用于在线冲击测量的大变形织物基应变传感技术

Largely deformable fabric sensor matrix for on-line impact measurement

防冲击与碰撞保护领域要求材料与装置具有柔性和大变形的特征,现有测量技术不能达到此要求,因此,有必要发展相应的测量技术,在线得到瞬间的应力/应变分布,作为评估材料与装置防冲击与保护性能的基础依据。首次研发了一种新型、柔性、可测量冲击大变形的纺织基应变传感技术,并应用于防弹材料的高速冲击在线测试。其中织物应变传感单元,测量范围可达60%,且满足不同应变率(0.05～1 000 s-1)的电力学响应要求。模拟力学领域的黏弹性理论,建立了表征应变传感单元的电力学模型,并用高速冲击试验验证模型。织物应变传感器连接电路以针织结构为基体,将细金属丝形成线圈结构,可承受160%的拉伸变形。为实现传感单元与针织电路的可靠电学连接,建立了一种弹性的连接模型。在防弹材料的高速冲击测试中,良好的电学信号输出显示了此测量技术的实用性。

Applications in impact protection, buffer and damping require materials and devices to be flexible and largely deformable, which however can not be handled by the existing technologies. Thus, it is valuable and necessary to in-situ measure the large stress/strain distribution for evaluation of the performance. A new, flexible and largely deformable fabric sensor matrix has been developed, where sensor unit is able to measure strain up to 60% with different strain rate from 0.05 s-1 to 1 000 s-1 To integrate sensor units onto different positions of the matrix, a knitted interconnect has been fabricated, which can be stretched up to 160% strain without changing electrical resistance. Meanwhile, a spring- like pattern has been built up for reliable and intimate contact between sensor electrodes and knitted interconnects. To evaluate the newly developed fabric sensor matrix, a complete measurement system was established and prototypes were tested on ballistic material in bullet-shooting processes. Results show that the sensor matrix can provide reliable measurements of large strains on the ballistic material with the short impact period. The technology of fabric sensor matrix is proved effective in on-line impact measurement and performance evaluation in various application fields.