REPORT ON THE RESULTS OF MECHANICAL TESTS 

 CARRIED OUT ON SOME MALAYAN TIMBERS. 



No reliable data has boon published of the mechanical properties 

 of the Malayan timbers and tho lack of such has been frequently 

 commented upon. It is with a view to supplying some approximate 

 figures relating to the properties of the local timbers that these notes 

 are put together. Originally the tests were made on a few selected 

 timbers to determine their suitability or otherwise for use in 

 aeroplane construction and it was intended that the tests should be of 

 a preliminary nature only, and that specimens of timbers thought 

 to be suitable would be sent to England to have tests of a more 

 detailed nature carried out upon them. It was soon found that the 

 result of the tests might be of more general use than for the 

 specialized purpose originally intended, and the scope of the investi- 

 gation was therefore enlarged and the figures tabulated below are 

 taken from tests made on 689 specimens. As noted above the tests 

 can only be accepted as of a preliminary nature for although some 

 considerable care has been taken to make the tests as accurate as 

 possible yet the lack of a suitable machine and suitable measuring 

 apparatus has been severely felt. A further difficulty in obtaining 

 suitable seasoned material has necessitated a number of unseasoned 

 specimens being used in the test, rendering strict comparison 

 between the various tests difficult. On the other hand the tests may 

 be said to have been made on material similar to that used in good 

 general construction, and may therefore be accepted as a guide in 

 future design. 



'2. The tests were carried out on specimens in cross bending 

 and the results are therefore most applicable to beams used to resist 

 bending moments. No tests were carried out under Compression, 

 direct shear or impact nor was any attempt made to compare 

 the hardness of the various timbers as the machine available 

 was not adaptable for such tests. For purposes of comparison 

 it should be noted that the tests were carried out on specimens 

 approximately 2" x 1" in cross section and the results reduced 

 to the recognized square inch basis. This is mentioned as it 

 has been found that results obtained from small specimens 

 are in general higher than those obtained from specimens of a 

 larger cross section. All tests were carried out on an " Avery " 

 2-Ton Machine using the "three point suspension" method; the 

 specimens being loaded centrally and supported on rigid supports 

 18" on either side of the centre. In general the loads were applied 

 by hand in \ cwts. increments at the rate of 1 ton per hour. The 

 deflections of the beam were measured after each increment of load 

 and were determined by the movement of the timber at the point 

 of load. No allowance has been made for local crushing which was 

 small in most cases. The apparatus to hand did not permit of a 

 more accurate determination of the deflection. The curve connecting 

 load and deflection for each^jae^mfin^w^s plotted and the yield 



