Tensile Strength Properties of Tropical Hardwoods in Structural Size Testing
In Malaysia, there is no research done on the tensile strength of structural size timber. The tension stress found in the Malaysian code of practice, MS 544: Part 2: 2001, was not determined directly and it was taken as 60% of the bending strength values of small clear specimens. This paper presents the results of the tensile test on structural size timber specimens from selected Malaysian Tropical hardwoods namely Kedondong (Canarium spp), Keruing (Dipterocarpus spp) and Bintangor (Calophyllum spp) under the strength group SG5. A special tensile grip was fabricated using the model suggested in ASTM D198 and the tests were also conducted according to ASTM D198. The tensile strength characteristics evaluated include tensile strength, modulus of elasticity and Poisson’s ratio, and the data were analyzed statistically. In this study it was found that the grade stresses for structural size specimens were higher than that published in the Malaysian code of practice. Index Term— tensile strength, structural size, Malaysian
Investigation of Linearity between Mechanical Properties of Wood Using Graphical Method
Some basic requirements are set for small clear specimen data to incorporate Malaysian timbers into equivalent European timber strength classes. In general, the correlation between structural and small clear specimen test results must be established for every timber group regardless of origin. This paper introduces a sort-plot technique for analysing the correlation of some mechanical properties of timber in selecting appropriate parametric model. Bending test was conducted on mixed species hardwoods for the determination of strength and stiffness values of both structural and small size specimens. The results showed that the sort-plot diagrams demonstrate an obvious linearity pattern between timber properties despite having poor regression values. The technique verified that properties of timber in structural and small size specimens correlated linearly.
Self-assembly of pyridinium-tailored anthracene amphiphiles into supramolecular hydrogels.
The mixing of a polyacid cross-linker with a pyridinium-functionalized anthracene amphiphile afforded a supramolecular hydrogel through a self-assembly process that was primarily driven by π-stacking and electrostatic interactions.