A contact free measurement method to determine internal stress states in glulam

被引:24
作者
Jönsson, J [1 ]
Svensson, S [1 ]
机构
[1] Univ Lund, Linkoping Inst Technol, Div Struct Engn, S-22100 Lund, Sweden
关键词
glulam; cross-grain direction; contact free measuring technique; released deformation; modulus of elasticity; internal stress; accuracy of measuring;
D O I
10.1515/HF.2004.022
中图分类号
S7 [林业];
学科分类号
0829 ; 0907 ;
摘要
A method to determine the internal stress state across the grain of glued laminated wood (glulam), as well as the experimental equipment for measuring released deformation are described in this paper. The internal stress state is calculated from measured released deformations, which are measured by a contact free method based on a digital camera technique. Nondestructive measurement of the modulus of elasticity in the crossgrain direction is presented and the correlation between dynamic and static modulus of elasticity is shown. Results for a single specimen with induced moisture gradient show that the largest stress found in the tests was about 0.57 MPa, which is higher than the characteristic value of tensile strength perpendicular to the grain. This stress is based on released strain over the total length of the slices cut from the specimens. FEMsimulations evaluating the stress distribution within the specimen to account for end effects indicate that the maximum stress is about 30% higher.
引用
收藏
页码:148 / 153
页数:6
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