Рубрика: High-Performance Construction Materials

Lamb-wave-based approach

Lamb waves are the most commonly used plate waves for health monitoring of plate-like structures. The propagation of a Lamb wave depends a great deal on the selected frequency and the material thickness. The Lamb-wave-based approach has been successfully applied to the health monitoring of composite structures, metallic structures and steel — reinforced concrete structures. […]

Vibration-characteristic-based approach

The vibration-characteristic approach utilizes the piezoelectric actuator to generate certain wave to propagate in the structure and compares the structural vibration-characteristic parameters (modal shape, model frequency, damping, stiffness, etc.) or vibration-characteristic response curves (frequency response, time response, transfer function, etc.) with those of the healthy state to detect damage. Piezoelectric-based active sensing system is commonly […]

Impedance-based approach

The impedance-based qualitative health monitoring technique is a real­time structural damage detection method. Due to the electromechanical coupling property of piezoelectric materials, the measured electrical impedance is directly related to the mechanical impedance, and will also be affected by the presence of damage. Sun et al. [39] conducted an automated real-time health monitoring system on […]

Application of piezoelectric material to structural health monitoring

In recent years, piezoelectric materials have been successfully applied to the structural health monitoring of composite structures, metallic structures and concrete structures. Extensive theoretical and experimental research has been conducted. The piezoelectric-based health monitoring approach is a nondestructive evaluation (NDE) method that is suitable for health monitoring of inaccessible in-situ civil structures without using additional […]

Shape restoration using superelastic SMAs

There is a specific type of application of superelastic SMA wires for structural control purpose that is different from the aforementioned examples. This application uses the shape restoration property of superelastic SMA wires. For example, Sakai et al. [37] researched self­restoration of a concrete beam using superelastic SMA wires. The experimental results show that the […]

Application of Active SMA Devices for Structural Vibration Control

9.8.1 SMAs for active structural frequency tuning For a structure vibrating at its resonant frequency, the vibration can be reduced by actively tuning the resonant frequency of the structure. Upon heating, SMA actuators embedded or installed in structures will increase the stiffness of the host structure, so that the natural frequency of the structures can […]

SMA braces for frame structures

The SMA wire braces are installed diagonally in frame structures. As the frame structures deform under excitation, the SMA braces dissipate energy through the stress-induced martensitic transformation (for the superelastic SMAs) or the martensitic reorientation (for the martensitic SMAs). Several different scaled-down prototypes of the SMA braces were designed, implemented and tested. The examples include […]