Metallic & composit structures

The visual inspection of welds is the first non-destructive test to be performed on welded joints and represents an important preliminary check of the quality of the welded joint. The inspection is carried out using optical tools, such as magnifying glasses or borescopes, and allows the detection of surface defects such as cracks, porosity, lack of fusion, undercuts, or geometric irregularities. This method enables the assessment of the welds’ compliance with project specifications and current regulations. UNI EN ISO 17637.

The magnetic particle inspection is a non-destructive testing method applied to welds in ferromagnetic materials. The principle is based on detecting surface and subsurface discontinuities by using ferromagnetic particles applied to an induced magnetic field. Discontinuities interfere with the magnetic flux and cause visible accumulations of particles. This method is particularly useful for detecting cracks, inclusions, and welding defects that are at or near the surface. Reference standard: UNI EN ISO 17638.

The ultrasonic examination is a non-destructive technique that allows for the detection of internal defects in welds, such as cracks, porosity, lack of fusion, or inclusions. The method is based on the propagation of ultrasonic waves within the material, which are reflected at the discontinuities. The analysis of the reflected signal allows for locating and assessing the size and nature of the defect. This examination is performed with a special probe and portable equipment. Reference standard: UNI EN ISO 17640.

Thickness testing is a non-destructive technique used to determine the thickness of metallic materials or protective coatings (paints, galvanizations, etc.) using ultrasonic or magnetic induction devices. This test allows for the assessment of the integrity and state of conservation of structural elements or components subject to degradation, corrosion, or wear, without the need to remove material. UNI EN 14127

Resistographic tests are a semi-destructive technique used to assess the condition of structural wood, particularly in historical buildings or those affected by biological degradation. The method involves inserting a rotating probe into the wood, recording the resistance encountered along the depth. The resulting profile (resistogram) allows for the identification of discontinuities, internal cavities, degradation, or loss of density. The investigation is localized and minimally invasive. RILEM, CNR DT 201/2005.