Continuous exploitation of bridges causes their progressive consumption. Periodic observations can help to control safety of such structures. Reliable description of behaviour of the bridge under load requires the use of method, which enables observation of many points simultaneously. The paper presents a comparison of deflection and vibration measurements performed on span of a steel bridge de...

In this paper, the advantage of an adaptive damping system is presented. A damper with variable stiffness is tuned based on estimates of the real-time frequency response, facilitating optimal vibration mitigation. The performance of the developed routines is investigated on an existing tied arch railway bridge. Based on previous field measurements, resonant behaviour of several hangers was foun...

Crossties and cable networks are used on cable-stayed bridges to mitigate wind-induced stay vibration. A nonlinear free-vibration analysis of a cable network with random oscillation amplitudes is presented in this study. Specifically, a nonlinear restoring-force spring model is introduced at the crosstie to simulate in-plane network free vibration at large amplitudes. The current constitutive m...

b fast and highly reliable method of inspecting minule solder joints of high-density rnouaed devices hns been dcveloperl. It uses two techniques to detect all types of defects, such as unsoldered leads. solder bridges. and mis-aligned leads. One applieszxternal Form to solder joints with an air jet. which vibrates w shifts unsoldered leads. The vibration and shift is detected as a change in the...

Flexible structures (such as long-span suspension bridges which undergo wind or earthquake excitations) exhibit complex dynamic behavior. Due to high cost of strengthening such structures, as well as the technological advances in recent years, much attention has been given to using innovative means of enhancing structural functionality and safety against natural hazards. Among the methods used ...