#Product Trends
Shear Test --ASTM D143 Standard Test Methods for Small Clear Specimens of Timber
Shear Test --ASTM D143 Standard Test Methods for Small Clear Specimens of Timber
Shear Parallel to Grain
1.This section describes one method of making the shear-parallel-to-grain test that has been extensively used and found satisfactory.
2.Size of Specimens-The shear-parallel-to-grain tests shall be made on a 2 by 2 by 2-1/2 in. (50 by 50 by 63 mm) specimens notched in accordance with Fig. 21 to produce failure on a 2 by 2 in. (50 by 50 mm) surface. The actual dimensions of the shearing surface shall be measured (see 22.2).
3.Procedure-Use a shear tool similar to that illustrated in Figs. 22 and 23, providing a 1/8 in. (3 mm) offset between the inner edge of the supporting surface and the plane of the adjacent edge of the loading surface. Apply the load to and support the specimen on end-grain surfaces. The shear tool shall include an adjustable crossbar to align the specimen and support the back surface at the base plate. Take care in placing the specimen in the shear tool to see that the crossbar is adjusted, so that the edges of the specimen are vertical and the end rests evenly on the support over the contact area, Observe the maximum load only.
4.Speed of Testing-The load shall be applied continuously throughout the test at a rate of motion of the movable crosshead of 0.024 in. (0.6 mm)/min.
5.Test Failures-The failure shall be sketched on the datasheet. In all cases where the failure at the base of the specimen extends back onto the supporting surface, the test shall be culled.
6.Moisture Content-The portion of the test piece that is sheared off shall be used as a moisture specimen.
