Abstract

Info

Title:: Research on Impact Damage Monitoring of PVA-ECC Beam After HighTemperature Based on Piezoelectric Active Sensing Technology

Author(s):: QI Bao-xin; LI Mo; LIU Dong; SONG Gang-bing; School of Civil Engineering, Shenyang Jianzhu University

Keywords:: high-temperature damage; PVA-ECC beam; impact performance; wavelet packet analysis; piezoelectric ceramic intelligent aggregate; structural health monitoring

Abstract:: The damage characteristics of PVA-ECC beams with high temperature damage under low velocity impact load were studied. A series of low speed impact tests were carried out to simulate the impact energy on the beam by comparing the temperature damage with the PVA-ECC beam at room temperature, the same drop height and drop hammer quality. The rule of crack evolution and wave attenuation were detected by the active detection method and frequency sweep signal of piezoelectric ceramic intelligent aggregate of PVA-ECC beam under falling hammer and low velocity impact. The PVA-ECC beam crack development quantization based on the wavelet packet energy analysis repeated impact test. The three dimensional finite element of PVA-ECC beam was established. Based on the finite element analysis method, the whole process of crack development of PVA-ECC beam after 300 ℃ high temperature was obtained. The results show that the impact resistance of PVA-ECC beam is weakened by high temperature damage, and the PVA-ECC beam has a certain anti-impact ability at ambient temperature, but when the temperature is 230 ℃, it reaches the melting point of PVA fiber, the PVA fiber in PVA-ECC beam disappears, the pore is produced, and the cement mortar beam is formed. It does not have the ability of resisting impact, so high temperature damage results take the strength, toughness and fatigue resistance in PVA-ECC away.