Technical Tips

Sharing knowledge gained from investigating the fundamental causes of failure.

Remember corrosion exacerbates the potential for fatigue failure

AUGUST 2017

Fatigue of engineering materials and their degradation through micro-cracking, as a result of cyclic loading, is extremely common in materials, especially metals and alloys, accounting for up to eighty percent of all structural failures. Real world engineering structures are subjected to a range of environmental conditions, which can and usually do exacerbate the fatigue circumstances and accelerate the fatigue crack advancement process.

Read more

The pros and cons of galvanic coupling

JULY 2017

Cathodic protection is a method of reducing the rate of corrosion damage to a metal surface by supplying it with electrons from an external source, effectively forcing it to become the cathodic (passive) element of a galvanic cell.

Read more

Don't discount small critters and biological growths.

JUNE 2017

Microbial Induced Corrosion can cause rapid localised attack and degradation of many metals including stainless steels.

Read more

Beware of highly stressed components working in a corrosive environment

MAY 2017

The combined influences of tensile stress and a corrosive environment can lead to catastrophic failure of susceptible materials by stress corrosion cracking mechanisms (SCC). Often these failures occur after relatively short periods in operation without warning, but with proper understanding and care, SCC can be avoided.

Read more

Don’t preclude DIC

APRIL 2017

Digital Image Correlation (DIC) is a non-contact optical technique for the analysis of surface displacement fields of a specimen during deformation/loading. This information can be used for subsequent analysis of the surface strain and has the potential to allow for continual in-service monitoring of components.

Read more

Value your tyres

MARCH 2017

Accurate modelling of material properties is vital in numerical analyses where changes in material properties can have a significant effect on the results of numerical analyses such as those employed in the modelling of automotive tyres.

Read more

Temperature effects on mechanical property performance.

FEBRUARY 2017

In today’s ever more stringent economic climate, reliable material performance is becoming even more important, as premature failures are not readily tolerated, especially when they can be anticipated and avoided. Sometimes such failures are related to the temperature behaviour of materials, and this month’s Technical Tip refers to two examples that illustrate such temperature related failures.

Read more

Overlook stress concentrations at your peril

JANUARY 2017

The effect of stress concentrating features such as notches, fillets, grooves and threads, has been known for many years and has been documented in many texts. However they are often overlooked and cause failure by locally increasing stresses and aiding fatigue crack imitation.

Read more

Preserve your fracture surfaces or lose information

DECEMBER 2016

When a component fractures, the atomically clean fracture surfaces contain many features indicative of how and why the fracture occurred. Preservation of these fracture surfaces is one of the most important aspects of any failure investigation and precautions should be taken to provide the failure analyst with a sample in the best possible condition for accurate assessment of the failure scenario.

Read more

Diffraction based residual stress analysis

OCTOBER 2016

Diffraction techniques, using both X-rays and neutrons, enables residual stress profiles of varying depths to be developed for the component in question. Although the cost of these processes and difficulties associated with their application generally limit these techniques to scientific applications, they are viable in certain industrial applications.

Read more

Micro-CT scanning is a novel alternative to conventional non-destructive testing

SEPTEMBER 2016

The micro computational tomography (CT) scanning of components is becoming an increasingly attractive option for the non-destructive testing of components both prior to and during service.

Read more

Laser shock peening is a novel technique for introducing beneficial residual stresses into components

AUGUST 2016

The controlled introduction of compressive residual stresses into the surface layers of components can effectively delay the onset of crack initiation and slow down crack growth rates. Laser shock peening is one such technique of introducing these residual stresses.

Read more