mechanical properties

The mechanical properties have been determined using the test procedure described in ASTM designation: D143-52 developed by the American Society for Testing Materials.

Strength Group

Four strength groups are used, viz., strength groups A, B, C, and D.  The earlier grouping method (Burgess, 1958) based solely on compression strength parallel to grain is given in the table below.

 

STRENGTH GROUPING TABLE
Strength Group	Compression strength parallel to grain (N/mm2)
A	> 55.2	extremely strong
B	41.4 - 55.2	very strong
C	27.6 - 41.4	moderately strong
D	< 27.6	weakest

A refinement to the earlier method took into consideration the basic and grade stressed (Engku Abdul Rahman, 1960). Some timbers have been grouped using this method.  For the remaining timber, the earlier grouping has been used.

Static Bending

Data on the Modulus of Elasticity (MOE) and Modulus of Rupture (MOR) have been obtained from published test data (Lee et al, 1979).  The mean values are given in the air-dried condition (unless otherwise indicated).  If a range is given, it shows the lowest and highest for the timber group.

Compression Strength

Data on compression strength perpendicular to grain and compression strength parallel to grain have been obtained from published test data (Lee et al, 1979).  If a range is given, it shows the lowest and highest values found for each timber.

Shear Strength

Data on shear strength have been obtained from published test data (Lee et al, 1979).  If a range is given, it shows the lowest and highest values found for each timber.

source from Malaysian Timber Council