Study on specimens shapes for tensile test of Malaysia bamboo

Abstract

In Malaysia, the bamboo is rarely used in structural elements due to the lacks of understanding on the feasibility and potential of bamboo and its behavior when subject to load. The strength should be fully understood as the structure is intended to take higher loads. Till now, the strength data for Malaysia bamboo is unavailable. Thus, testing on bamboo should be done to get the correct data. However, the tensile procedure on specimen preparation suggested by many codes lead to incorrect failure modes where most of the tensile test end-up with failure at the grip rather than at the gauge length or between the grips. Therefore, thorough investigation on the specimen shape is needed to ensure that the correct failure modes is obtained. Bambusa Vittata was prepared and cut into strips with average size of 200 mm long, 15 mm wide and 9 mm thick. The specimens were then trimmed to the required shape. A total of 20 specimens were divided into four groups with different shapes, namely S (strip cut), SS (strip cut-side curve), DC (double curve) and SC (single curve). Tensile strength tests were carried out on these four groups with average dry moisture content between 9 % -16 % after air-dried. Based on the testing, the results show that the appropriate cutting pattern for tensile test was SS, followed by DC, S and SC. The failure pattern of bamboo occurred for SS was exactly at the gauge length area as compared to the other specimens with maximum average stress and strain of 201.9 kN/mm2 and 1.227 % respectively.