This Tech Tip follows closely from the previous one in which the importance of accurate evaluation of the stresses in engineering design was highlighted. The sentiments expressed in this previous Tech Tip, focussed on the importance of the reliable estimation of loads and theoretical analysis of stresses during design and comparison of these estimates, to […]

A great deal of the work with which Origen is involved, is concerned with failure analysis and fracture mechanics. Both of which require realistic and accurate assessment of loads and hence stresses to which the component or system is subjected. These loads/stresses may be obtained in various ways, and a good starting point is often […]

A significant number of injuries and deaths have been attributed to the improper use/failure of ladders and Origen has been involved in a number of investigations/ legal cases related to their failure. These failures occur in both the work and home environments and in some cases involve relatively new ladders. In order to mitigate, there […]

From the perspective of atomic and molecular models of metals, the strength of a material is reached when there is separation of two surfaces within a crystal. This simple assumption and some analysis leads to predicted theoretical ‘strengths’ in the order of E/8 (where E is Young’s modulus). When more rigorous assumptions and the effect […]

Following from our previous tech tip which addressed some of the key elements associated with NDT, this Tech Tip discusses some of the more commonly used NDT techniques. For External (Surface) Flaw Detection, the NDT process typically starts with Visual Inspection, which can be enhanced by Dye Penetrant. Crack like defects can be readily manifest […]

In this modern age of design and manufacture, an essential complementary corollary to fabrication is the assessment of the component or structure, to ensure that it is ‘fit for purpose’. It is one thing to design the engineering system, and quite another to ensure it is made to the specifications envisaged, and, critically, that it […]

In many failure investigations, interpretation of the features on the fracture surface (or surfaces) can be extremely useful in determining the mode of failure. One of the most interesting and revealing features is that of micro-void coalescence (MVC). Micro-void coalescence is a high energy fracture mechanism in metals, which is very common and readily interpreted. […]

Flow Accelerated Corrosion (FAC) refers to a wear mechanism which results in severe wall thinning (up to 3mm/year) and metal loss of carbon steel piping and vessels exposed to flowing water and wet steam. FAC is often occurs in power generation units, including both conventional plants as well as nuclear facilities worldwide, but also occurs […]

The joining of components or structures is an essential feature of engineering and the practice of bolting components is ubiquitous. Despite its widespread appeal and usage, however, bolting is not a trivial exercise, and disregard of the fundamentals or lack of awareness of the subtleties associated with bolting, has led to some catastrophic failures. This […]

Corrosion, at the most basic level, may be considered as the dissolution of a metal in the presence of an aqueous solution (such as water). When metal corrodes in an aqueous solution such as oxygenated water, the metal anode is oxidised to form metal ions (typically M+), releasing electrons in the process. The electrons are […]