| Fire caused severe damage to wood structure.The present study of fire resistance behavior on post-beam timber frame and post-disaster assessment method is still in the basic exploration stage.How to complete the detection and identification of the timber frame simply and assess its structural safety after the fire is an important issue need to be resolved.A post-beam timber frame with steel-wood bolted connnetions is designed, and is put onfire according the ISO834 standard heating curve. Fire is extinguished after 10 minutes and 20 minutes. the comparison of timber frame is summaried and charring speed laws after different fire duration and fire damage mechanism of wooden frames is studied.Small specimens from the wood component after fire are made, and Resistograph are used to test these specimens. Then small timber specimens are used to do Wood Properties tests, including density, compressive strength parallel and perpendicular to grain, flexural strength, shear strength and modulus of elasticity parallel to grain. The relationship between the small specimens’ properties and the resistance values are fitted curve.Based the linear regression equation by small specimens after fire obtained on the foregoing, wood properties of timber frame after fire could be calculated by resistographic tests. Considering the differences between small timber specimens and wood members, the residual strength of timber frame members can be obtained.Finally, to study basic mechanical properties, the ultimate bearing capacity and the broken law of timber frame after the fire, ultimate bearing capacity of the timber frames which are carried out NDT are tested. Abaqus is used on analyzing the bearing capacity of them, using the wood properties by NDT. To comparing the calculation results with test results. The feasibility of non-destructive testing of wood after fire combining finite element method to achieve the remaining bearing capacity of wooden structures is verified. |
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