Stress and Materials Testing

The Department has carried out contract testing and consultancy for local and national companies for many years.

The expertise in the Department combined with extensive test facilities has provided a competitive and reliable resource for industry. Although operating within an academic environment, the Department has proved responsive to the demands of industry.

This page highlight some of the test and consultancy work that has been carried out within the last couple of years. The Department has access to the facilities of Oxford Brookes University as a whole and we would be pleased to discuss with companies any projects or requirements they may have.

Fatigue and Proof Testing

Fatigue and Proof Testing

The carbon composite components shown were fatigue and tensile tested for Oxford Magnet Technology. This is one of many contract testing jobs carried out for local and national companies. The group has NAMAS calibrated facilities with capacity ranging from 1 kN up to 500 kN.

The Department also carries out a variety of proof load tests for companies. This includes proof testing of production runs, for which we have gained a reputation for fast and reliable delivery of results.

Photoelasticity

Photoelasticity

The Department has developed expertise in the use of photoelastic techniques for determining stress profiles in components. This includes freezing photoelastic materials to retain profiles and the use of photoelastic coatings. The picture above shows the stress profile generated in a con rod which was being designed for use in a particle accelerator facility.

Optical Micrographs

Optical Micrographs

The micrographic sections shown were used to assess the forming production process for threaded rods.

In addition to microscope and material preparation facilities the group has access to scanning electron microscopes.

Strain Gauging

Strain Gauging

The Department has been involved in the application of strain gauges for many years and has very close ties with the British Society for Strain Measurement. Some very specializes strain gauge projects have been undertaken by the group such as the gauging of holes and the measurement of residual stresses. The picture alongside shows a specimen which has two gauges bonded inside a 6mm circular hole.

Transducers

Transducers

The Department is very experienced in the design and application of transducers. The 300 Nm transducer shown was designed and used to measure the torque in a vehicle part to an accuracy of 0.1% of the full range.

Calibrations are also performed by the group for a variety of companies at elevated, room and cryogenic temperatures. We deliver fast and reliable calibrations for companies wanting to use our facilities as part of their production process.

Static Load Testing

Static Load Testing

The picture (oval) shows a car component being tested on an Avery Dennison torque machine. This testing formed part of a large research contract on the use of adhesives in car bodies. This work was carried out with the Joining Technology Research Centre at Oxford Brookes University. We have the facilities to test in torsion, bending, tension and compression with loads measured accurately to fractions of a newton.

High Speed Photography

Members of the Department have expertise in the capturing of high speed photographs of ballistic or high speed impact events.

High Speed Photography

The photograph shows a grid on a deforming torsion specimen taken at a framing rate of 35,000 /s. This work was carried out in conjunction with the University of Oxford.

Finite Element Analysis

Research and consultancy on analytical and Finite Element modelling across a broad range of materials and components has been carried out by the Department. This work involves both static and dynamic modelling with special interest in composite materials. The picture below shows a Finite Element model of a ceramic-metal joint which was developed as part of a research project.

Finite Element Analysis

Cryogenic Testing

An increasing amount of contract test work at cryogenic temperatures is being carried out by the Department. The setup shown is for the mechanical testing of a component manufactured by Oxford Instruments Technology Development Group. This work has expanded beyond consultancy leading to involvement in research aspects of cryogenic testing. The Department is steadily developing as a centre of excellence in this area.

Available facilities

The test work and research carried out in the Department is supported by extensive facilities that include, cryogenic test chambers, photoelastic benches, a moiré interferometry rig, tensile test machines, servo-hydraulic test machines, high temperature test furnaces, an Avery Dennison torque machine and several rotating bending fatigue machines. In addition the Department has at its disposal considerable strain gauge instrumentation facilities and expertise.

The capabilities of our tensile and torsion test machines are shown below:

Machine

Test Type

Range

Calibration

Accuracy

Dennison

Torsion

300 Nm, 1.2, 12 kNM

300 Nm (In house)

>1% FSD

Testometric

Tensile (& variants)

Auto-ranging 4N up to 50 kN

1998 (Supplier Calibration)

1% FSD

Mayes 100

Tensile (& variants), Fatigue

0.5, 1, 2.5, 5, 10, 20, 50, 100 kN

NAMAS - All Ranges

1% FSD, 0.5% FSD in some tension ranges

Mayes 500

Tensile (& variants), Fatigue

50, 100, 250, 500 kN

NAMAS - All Ranges

1% FSD, 0.5% FSD in some tension ranges

ESH

Tensile (& variants), Fatigue

20, 50, 100, 250 kN

NAMAS - All Ranges

1% FSD

All the tensile test machines have associated extensometers. The extensometers for the Mayes 100, 500 and ESH machines are NAMAS calibrated to an accuracy of 1% FSD. Data can be recorded directly onto X-Y plotters or can be captured using a data logger for latter manipulation on a computer.

The high temperature test furnaces can be used with the Mayes 100 and ESH servohydraulic machines and provide the facility to test in tension or compression up to 1000°C.

CONTACT DETAILS

Department of Mechanical Engineering and Mathematical Sciences

Oxford Brookes University
Wheatley Campus
Wheatley
OXFORD OX33 1HX
United Kingdom