基于小波理论对混凝土损伤特性的试验研究

针对几种不同强度等级的标准混凝土立方体试块进行了冲击加载试验,对冲击荷载作用后混凝土的损伤特性进行探索性研究。研究表明:冲击载荷作用下不同强度混凝土损伤变化幅值不同,其内部损伤表现出各向异性,混凝土强度越大抗冲击能力越强;利用超声波波速来描述材料内部损伤,并由小波变换消噪方法对超声波信号处理后,首波到达时间(声时)的判读既准确又合理;超声波信号经小波分解后各频段能量分布规律随损伤变化有较明显的变化,采用某一频段能量分布描述损伤,表明能量比声速对损伤更敏感。

EXPERIMENTAL STUDY ON DAMAGE CHARACTERISTICS OF CONCRETE BY USING WAVELET THEORY

A series of standard cube concrete of different grades were tested under impact load to study the damage characteristics of concrete.The experiments indicate that concrete of different grades under impact load has different ranges of damage;its interior damage is anisotropic;and its resistance to impact increases with the increasing of its strength.The interpretation of arrival time of head waves is accurate and reasonable by using ultrasonic velocity to describe material interior damage and wavelet transform noise cancellation method to treat ultrasonic signals.Regularities of energy distribution in each wave band have evident changes with the change of damage after the decomposition of ultrasonic signals by wavelet.It also illustrates that energy is more sensitive to damage than ultrasonic velocity is when energy distribution in one wave band is used to describe damage.