Axial crushing of thin-walled structure with crease lines

Thin-walled structures receive much attention as energy absorbing device because of its cost advantage. Apart from being energy absorbent, efficient energy absorbing devices should also have low initial peak force, so that no excessive force is transmitted to the structures that needed protection. Thus, this paper focuses on the role of crease lines of patterns, applied to the surface of thin-walled structure to the produced initial peak force and collapse pattern. Two types of thin-walled structures which are pre-folded with horizontal and inclined crease lines are investigated with finite element analysis. The results show that thin-walled structures having pre-folded inclined with horizontal crease lines exhibit lower initial peak force when compared to the thin-walled structure with only pre-folded horizontal crease lines and benchmark thin-walled structure with no crease lines

VALIDATION OF SHEAR FAILURE ON BOLTED CONNECTION FOR NYATOH HARDWOOD

The lack of consideration of brittle failure by the Malaysian Timber Standard (MS544-5) in the design of bolted connections for local hardwood can be seen from the unacceptable under-design performance shown by the code. This makes the design output costly because of the increased use of steel materials due to either bigger bolt diameters or larger bolt quantities required. The current study was conducted to examine the effectiveness of the existing design equations for bolted connections in Nyatoh hardwood. This present study was to propose a set of optimised equations that can be used for the retrofit design of wall-diaphragm connections in unreinforced masonry buildings. The row shear failure observed in the tested bolted connections of Nyatoh hardwood was also reported. Ten different bolted connection configuration details in the manner of a steel-wood-steel arrangement were tested, which all had a single row bolted connection. By using the linear regression method in analysing the experimental data obtained, a calibration factor for optimising the Row Shear Model (RSM) equation was identified. From the comparisons made between the experimental results and the strength predictions given by both MS544-5 and RSM, it was found that the design strength calculated from MS544-5 was too conservative for predicting the bolted connection strength in Nyatoh hardwood, whereas the RSM predictions were acceptable and recommended