The determination of shear strength properties of various species of wood and adhesive bonds in wood by compressive loading are commonly established by performing large number of tests on small specimens, which are representatives of their parental materials.
Adhesives are commonly used in the wood industry for bonding thin layers of wood together to form plywood or as a quick and efficient method of joining various parts together. Since wood failure frequently occurs in bonded joints, it is therefore desirable to evaluate the shear performance of these adhesive bonds when they are subjected to compressive loads.
Some of the common international standards governing shear testing of wood and adhesive bonds in wood include ASTM D143, ASTM D905, ISO 6238, JIS K6802, JIS Z2117, BS 373, and JAS 601.
A suitable test set up for these tests includes a 3300 Series electromechanical testing machine, configured with a 50 kN load cell and the wood shear fixture. As in ASTM D143, the shear fixture should apply load to the test specimen through adjustable seat to ensure uniform lateral distribution of load. In addition, the JIS standards specify that specimen should be held in position firmly during the test.
It is challenging to design fixtures that are capable of meeting the different technical aspects set by various standards. For example, ASTM D143 states that the shear tool must provide a 3 mm offset between the inner edge of the supporting surface and the plane of the adjacent edge of the loading surface, while JIS K6802 requires this shear line to be offset by 2 mm.
To meet the different offset requirements set by multiple standards, the fixture should be supplied with clearance adjustment shims to allow the clearance along the shear line to be adjusted according to the standards you are testing to. Our wood shear fixture is designed in accordance to these standards.
We recommend using our Bluehill® 2 or Bluehill Lite materials testing software for setting up the test. It allows you easy configuration of different testing parameters in order to meet the specific test standards, and the software provides the result calculations required by most testing standards.
We recommend that you review the standards to fully understand its requirements.