non destructive testing

Non-destructive testing methods

Vibration analysis, infrared thermography, acoustic emission analysis, ultrasonic imaging, x-ray computer tomography, ground penetrating radar, digital radiography, optical testing methods, eddy current imaging, magneto-inductive cable testing

Vibration analysis Vibration analyses can be carried out on a wide range of structures such as bridges, dams, buildings, etc. The tests are designed to determine the dynamic characteristics of the structures such as natural frequency, modes of vibration and damping. The results are used to gain basic information for the

evaluation of earthquake safety, long-term monitoring, short-term condition tests and optimising of analytic models. The two methods available are «ambient vibration analysis» and «forced vibration analysis».

Infrared thermography Impulse excitation for large structures

IR thermography is a method for measuring the temperature distribution of a surface. It permits to detect regions of heat production (e.g. due to a crack under cyclic loading or a hot spot in a defective IC) or regions of inhomogeneous cooling (e.g. due to blisters

IR photograph

or air voids in a pavement or under waterproof membranes). In the building phase of road constructions, IR thermography can be used to control the temperature of the single components. When flashes or a sine-modulated radiator heat an object, voids and debondings buried below the

Phase display of a CFRP plate with defective bonding to concrete

surface hinder the heat transfer. The resulting transient thermal contrast on the surface is made visible with pulse or lock-in thermography.

Acoustic emission analysis

Acoustic emission analysis uses sensors mounted on the surface of parts or structures to record elastic

Acoustic emission analysis is also used for load tests carried out during investigations on a car chassis made of carbon fibre reinforced plastic.

waves caused