1. One test method of determining the tension-parallel-to-grain strength of wood is given in the following procedure.
2. Size of Specimens
The tension-parallel-to-grain tests shall be made on specimens of the size and shape in accordance with Fig.29. The specimen shall be so oriented that the direction of the annual rings at the critical section on the ends of the specimens, shall be perpendicular to the greater cross sectional dimension. The actual cross-sectional dimensions at minimum section shall be measured.
3. Procedure
3.1 Fasten the specimen in special grips (Fig.30) Deformation shall be measured over a 2in. (50mm) central gage length on all specimens. Take load-extension readings until the proportional limit is passed.
3.2 Deformations shall be recorded using displacement measurement devices that are capable of a Class A rating when evaluated in accordance with Practice E2309.
3.3 Fig.30 illustrates gripping devices and a type of extensometer that have been found satisfactory.
4. Speed of Testing
The load shall be applied continuously throughout the test at a rate of motion of the movable crosshead of 0.05 in (1mm)/min.
5. Sketch of Failure
The failure shall be sketched on the data sheet (Note 15)
NOTE 15-See Fig.31 for a sample tension-parallel-to-grain-data and computation sheet
6. Moisture Content
A moisture section about 3 in. (76 mm) in length shall be cut from the reduced section near the failure.
