Double Beam Sheer - Composite Material Mechanical Testing Tool


Double Beam Shear Composite Material Testing Tool

This novel test method developed at Loughborough University could revolutionise the interlaminar shear (ILS) testing of the composites used to build aircraft, ships and road vehicles - making them lighter, stronger and more fuel efficient without compromising safety.

Double Beam Shear is a new test method for determining the interlaminar shear (ILS) mechanical properties of composite laminates.

Composite materials – laminates comprising carbon, glass or aramid fibre reinforced plastics – are up to five times stronger than steel and a fifth of the weight.

Composites have many applications spanning the wind energy, aeronautical and automotive industries – including wind turbine blades, F1 cars, domestic and commercial road vehicles, ships and aircraft.

Vehicles built using these modern materials are lighter and more fuel efficient than those constructed from metal-based materials.

The Boeing 787-8 Dreamliner was the first commercial “plastic airplane”.  Its lifespan exceeds that of similar conventional aircraft – and it is greener.

What’s more, using composites to build the aircraft has yielded a 6% weight efficiency, resulting in

  • 16% improvement in fuel consumption
  • 14% reduction in cost per seat



Dr Gang Zhou’s novel Double Beam Shear testing technology has the potential to measure the interlaminar shear mechanical properties of composite materials with far greater accuracy and reliability than existing test methods.

Two current standard tests– the Short Beam Shear and Iosipescu Shear tests – require a substantial built-in safety margin at build stage. This means that vehicle sections are invariably heavier than is actually necessary.

Using the Double Beam Shear method, vehicles could be even lighter and therefore more efficient in terms of fuel consumption and CO2 emissions.

DBS combines a novel apparatus and test method that delivers accurate and reliable results, even when the analysed sample is comparatively small – 6cm x 1cm. 

The sample is clamped in a uniquely designed jig and broken. The force needed to fracture the section is fed into a bespoke mathematical programme and the exact physical properties of the material are calculated.

Knowing the precise durability and life-span of a given material means that vehicle designers and manufactures can dispense with excessive safety margins and design light-weight vehicles that do not compromise on safety and endurance.



The DBS offers industrial OEMs, composite materials and components suppliers, technical engineering services organisations and mechanical testing machine manufacturers the new and improved knowledge, research expertise and skills relevant to their business and hence for them to gain competitive advantages.

The DBS can help

(a)       support structure designers to achieve a more cost-effective and lighter-weight design;

(b)       help stress analysts, product development and modelling engineers to optimise structural performance with a lesser penalising safety factor;

(c)       help composite materials suppliers to extend the ILS performance envelope of the materials;

(d)       assist components manufacturers to deliver certifiable structural products;

(e)       help testing machine manufacturers to expand their products portfolios and

(f)       help government standards and regulations agencies to recommend a more cost-effective and technically best practice.


The DBS benefits all sector users of composite materials, ranging from aerospace and defence, land transport, marine, wind energy, oil and gas, technology service providers and standards regulating bodies.


Route to Commercialisation

The DBS test has been developed with collaborating partners including composite material manufacturers, material testing equipment (Instron) and services (National Physical Laboratory) as well as aerospace designers and manufacturers (GKN Aerospace).

The methodology’s accuracy, reliability and industrial application has been demonstrated using multiple composite materials, each with different lay-ups, thicknesses and width-to-thickness ratios. In particular, a reproducibility and repeatability of the DBS ILS strength and modulus have been demonstrated in the industrial round-robin exercise. A DBS Test Standard was submitted to the International Standards Organisation (ISO) in September 2013 and was accepted as a work item. It has since progressed from a work item to an ISO committee draft after successful balloting. The Idea has been approved to proceed in the relevant committee and work is under way and it is in the middle of international ISO members’ round robin exercise. See the link:

Loughborough University is now able to offer consultancy services spanning

  • Double Beam Shear testing of materials,  and comparison data for Single Beam Shear and Iosipescu – basic and detailed reports can be               provided
  • ILS modulus test analysis – basic and detailed reports can be provided
  • software licence for ILS modules calculation of Double Beam Shear
  • provision of the jig design plans

View The Double Beam Shear video on youtube


The development of the DBS technology has been supported with funding from the Engineering and Physical Sciences Research Council (EPSRC), the European Regional Development Fund (ERDF), the Higher Education Funding Council for England (HEFCE), the Nuffield Foundation, and Loughborough University as well as industrial collaborators.


Patent Information:
For Information, Contact:
Paul Burrows
IP Exploitation Manager
Loughborough University
Gang Zhou
Aeronautical Engineering
Aerospace Structures
Composite Laminates
Composite Manufacturing
Composite Materials
Composite Mechanical Testing
Composite Stress Analysis
Composite Structure Design
Composite Structures
Layered Materials
Reinforced Polymers
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