It is common knowledge that a structure needs to be inspected and certain tests are needed to be performed in order to ensure its safety. This is true to all vertical and horizontal projects which includes steel structures. And therefore you need the seven (7) test on the steel structure.
Checking a steel structure through various methods of welding tests is necessary. Although merely inspecting or visual evaluating the weldment will do the job, it is still important to try other methods. In this post, we are going to introduce to you seven testing methods that can be performed to check the stability of a steel structure.
Do you want to know what these are?
Apparently yes since you are on this page. Since proper inspection of a structure is very important, having accurate knowledge of what techniques are available is a prerequisite. Without performing tests, the expected life of a structure will be reduced and more money will be spent for its maintenance and repair.
So, what are the tests needed for steel structures? I will present them to you and give you a brief overview of each one.
1. Bend testing shear stud
This is a simple bend test which is used for checking a particular welding data. In this test, the weld is subjected to bending in a way that the area for examination is the tension zone. A bending moment of 60° or 30° is applied to a stressed area below its elastic limit. This test evaluates the ductility, brittleness, and soundness of welds.
2. Bolt tightening or torque test
Torque refers to the angular force that is needed for rotating something. It creates tension for threaded fasteners like bolt and nut. This kind of test is also known as fastener testing. Although high strength bolts are used as connectors in steel structures, it is still important these are tested to ensure that it can carry a particular load. There is no standard torque value for tensioning bolts but some engineers developed their own formulas which serve as their rule-of-thumb for the torque test.
3. Magnetic particle inspection test for welding
This welding test is a non-destructive technique (NDT) that will help detect the defects and discontinuities on the surface of a ferromagnetic metal like iron and steel. This is primarily used to test pipelines as well as other metal machinery components in order to avoid accidents and failures. In this test, the metal object is magnetized surrounding it with an invisible magnetic field. The magnetic particle testing will make it easier to identify defects through a disruption.
4. Ultrasonic test for welding
This one is based on the ability of high-frequency oscillations, which is about 20,000 Hz. It will propagate into the metal and it will be reflected from the voids, surface scratches, and other discontinuities. Diagnostic wave enters into the material. Graphical and parametric readings will show the nature of the defect that is recognized by the test.
5. Visual test for welding
Of all the welding tests, visual inspection is the simplest. But it is also the most underrated and underestimated because you do not need to use any equipment. Because of that, it is inexpensive and quick to perform. This non-destructive testing (NDT) is a method used to inspect completed welds aiming to avoid any problems in welding. The inspection can be done before, during and after the welding process.
6. Dye penetrant
This one is also a non-destructive testing technique. In this test, low viscosity liquids will be penetrated in the surface openings. After penetration, the liquid will be extracted again through of some developers. Since it used liquids, it is also called as liquid penetrant inspection (LPI). This method is used to locate surface-breaking flaws and discontinuities like cracks, laps, porosity, and seams. This can be applied to ferrous, non-ferrous and all non-porous materials.
This test makes use of X-rays from an X-ray tube or gamma rays from a radioactive isotope. Radiation, which penetrates the material, is passed through a solid object that results in an image of the object’s internal structure. This will then be reflected in the film similar to what we can see in medical X-rays. Cracks and low-density areas like slag will be shown as dark outlines in the film while high-density areas like tungsten are light areas. Discontinuities are determined by the shape and variation of density in the film.
Isn’t it good to know that you have a variety of choices when it comes to testing steel structures? However, you need to study each one well so that you will know which method to use. You need to bear in mind that not all the tests are advisable for all steel projects.
Also, take note that it is better to perform more than two tests in order to make sure that you will arrive at an accurate result. Although the visual inspection is the easiest method for welding tests, it may still be needed to proceed with other testing methods that use certain equipment. This way, you will get satisfying results. Now, I would like to hear your thoughts about this.