BioMatNet Item: FAIR-CT96-1638 - Extending markets for wood-based panels by developing a better understanding of shear test methods and board shear properties

FAIR-CT96-1638
Extending markets for wood-based panels by developing a better understanding of shear test methods and board shear properties

Contacts
Website: www.tradatechnology.co.uk/ttl/information/projects

To find similar Items, click on a keyword below:
FAIR Area 1.3 - Forestry-Wood Chain : Solid Wood Products : Wood (Lignocellulose)

	Type of Project	Shared Cost
	Contract No	FAIR-CT96-1638
	Total Cost	1 048 013 ECU
	EC Contribution	524 000 ECU
	Start Date	01/12/1996
	Duration	36 months

Abstract of final report as a PDF file

Objectives

The principal objective of the project is to facilitate the increased use of wood-based panels in applications where they are required to carry shear forces. This will be achieved by developing a better understanding of shear test methods and board shear properties and how these relate to the design and behaviour of components and structures.

Technical Approach

The existing test procedures for determining the shear properties of wood-based panels to be used in structural design within the Construction Products Directive (CPD) are included in EN789 as informative annexes because of the uncertainty concerning their use. Because of the uncertainty associated with the shear properties for wood-based panel products, the design values used have a high "safety factor" which makes the design of structures involving shear less efficient and less economic. Improvements and documentation of the test methods for shear would increase the level of confidence in the data and allow more economically viable design values to be used. This would then facilitate the use of panels in structures, which would otherwise be impractical or uneconomic.

Expected Results

The following are the main stages of the project being carried out:

Study of the history and development of shear testing of panels
Development of an understanding of shear behaviour by mathematical modelling
Sampling of the most suitable materials for testing
Improvement and documentation of EN 789 test methods for panel and planar shear
Possible correlations to a selection of international small scale test methods
Proposal for revision to EN 789
Verification of measured shear behaviour by component testing
Production of design guidance to facilitate the exploitation of the shear carrying potential of wood-based panels.

Results to Date

The first stage of the project is to develop better shear test methods, as the ones currently used to derive design values are considered to be conservative. Following computer modelling and trials of a range of test methods, the most promising methods have been selected and are now undergoing trials to verify their performance. If these are proved to be successful then a proposal will be made for the methods given in BS EN789 to be modified.

1999 will see testing of components such as I-beams and box beams to demonstrate the benefits of more accurate and reliable design values for shear. More information on the project is available on the project homepage at:

http://www.tradatechnology.co.uk/ttl/information/projects/ec/shear/shear.htm

Trada Technology have produced an Information sheet on Structural use of wood based panels which can be obtained from them.

Wood-based panels before (left) and after (right) shear testing

Contacts

Coordinator

Victor KEARLEY / TRADA Technology Ltd UNITED KINGDOM

EC Scientific Officer

Alexandros ARABATZIS / European Commission DG Research Theme 1 Key Action 5.3 / BELGIUM

Participant