基于PVDF的混凝土内应力传感器设计及应用

摘要

针对混凝土内部动态应力直接测量需求，设计制作了软基底的PVDF压力传感器，传感器为夹心式结构，PVDF压电薄膜厚度为50μm，传感器的有效工作区域为1 cm×1 cm的矩形。对传感器防护后将其直接埋入混凝土内部进行动态应力测量，获得了冲击压缩实验中混凝土内部动态应力的有效数据，实现了混凝土内部动态应力的直接测量。与应变片测得的应力信号相比，PVDF压力传感器测得的铝合金试件中应力峰值偏差为10.7％，混凝土中应力峰值偏差为19.3％。%To measure the internal-stress of concrete directly ,a kind of PVDF stress sensor of soft underlayer was designed . The PVDF film was conglutinated between two pieces of insulating film .The thickness of the PVDF film was 50 microns,and the ef-fective work area of the sensor was 1 centimeter by 1 centimeter .The sensor was encapsulated and then fixed inside the concrete specimen .The experiments were carried out ,and the internal-stress history of concrete was obtained .Compare with data obtained by strain gauge,the peak value of internal-stress of aluminium alloy and concrete obtained by PVDF stress sensor are 10.7%and 19.3%lower separately .