Analytical Model of Moisture Stress in the Cross-Section of Wood Member Under Non-uniform Moisture Gradient

doi:10.12068/j.issn.1005-3026.2025.20239050

Abstract

Abstract:

Establishing the moisture stress analytical model of wood members is the basis for studying the laws of wood shrinkage cracking and their impact on the bearing capacity. Firstly， the stress distribution model of cross-section under moisture content gradient was established by analyzing the stress balance in the cross-section of wood member. Secondly， the equilibrium conditions， physical conditions， geometric conditions and coordination equations for wood members under non-uniform moisture content gradient were established based on the temperature stress elastic analytical model and the thermo-analogy relationship. The analytical solutions of tangential and radial moisture stresses， critical moisture content of cracking and critical point of tangential tension and compression were obtained by solving the equations. Finally， the correctness of the analytical solutions was verified by numerical simulations. Taking Chinese fir members as an example， the influence of different parameters （moisture content difference， member diameter， initial and final moisture content values） on the radial and tangential moisture stress distributions of the cross-section of wood members was analyzed. The results show that the moisture stress distributions in the cross-section of the wood member is not related to the initial and final moisture content of the wood member and the size of the member， but is related to the moisture content difference and material properties.

Key words: moisture stress, cross-section of wood member, moisture content difference, non-uniform moisture content, analytical model

CLC Number:

TU 366.2

Pan-pan TIAN, Hong-xing QIU, Jian-hong HAN, Xia HAN. Analytical Model of Moisture Stress in the Cross-Section of Wood Member Under Non-uniform Moisture Gradient[J]. Journal of Northeastern University(Natural Science), 2025, 46(4): 144-150.

Figures/Tables 6

References 25

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组号	模型形状	截面半径R	初始含水率	平衡含水率	含水率分布形式	约束位置	含水率差Δw
组号	模型形状	mm	%	%	含水率分布形式	约束位置	%
1	圆盘	100	25	10	抛物线Δw(t,ρ)=Δw[2ρ/R-(ρ/R)²]	圆心	15
2	圆盘	100	25	20	抛物线Δw(t,ρ)=Δw[2ρ/R-(ρ/R)²]	圆心	5
3	圆盘	100	25	0	抛物线Δw(t,ρ)=Δw[2ρ/R-(ρ/R)²]	圆心	25
4	圆盘	150	25	10	抛物线Δw(t,ρ)=Δw[2ρ/R-(ρ/R)²]	圆心	15
5	圆盘	100	15	0	抛物线Δw(t,ρ)=Δw[2ρ/R-(ρ/R)²]	圆心	15

组号	模型形状	截面半径R	初始含水率	平衡含水率	含水率分布形式	约束位置	含水率差Δw
组号	模型形状	mm	%	%	含水率分布形式	约束位置	%
1	圆盘	100	25	10	抛物线Δw(t,ρ)=Δw[2ρ/R-(ρ/R)²]	圆心	15
2	圆盘	100	25	20	抛物线Δw(t,ρ)=Δw[2ρ/R-(ρ/R)²]	圆心	5
3	圆盘	100	25	0	抛物线Δw(t,ρ)=Δw[2ρ/R-(ρ/R)²]	圆心	25
4	圆盘	150	25	10	抛物线Δw(t,ρ)=Δw[2ρ/R-(ρ/R)²]	圆心	15
5	圆盘	100	15	0	抛物线Δw(t,ρ)=Δw[2ρ/R-(ρ/R)²]	圆心	15

方向	弹性模量	抗压强度	抗拉强度	干缩湿胀系数	方向	剪切模量	泊松比
方向	MPa	MPa	MPa	%	方向	MPa	泊松比
R	E_R=1 048	f_c,R=3.07	f_t,R=3.07	α_R=0.139	RT	G_RT=232	v_RT=0.43
T	E_T=594	f_c,T=2.67	f_t,T=2.67	α_T=0.255	RL	G_RT=967	v_RL=0.03
L	E_R=12 888	f_c,L=36.25	f_t,L=36.25	α_L=0.019	TL	G_RT=773	v_TL=0.02

方向	弹性模量	抗压强度	抗拉强度	干缩湿胀系数	方向	剪切模量	泊松比
方向	MPa	MPa	MPa	%	方向	MPa	泊松比
R	E_R=1 048	f_c,R=3.07	f_t,R=3.07	α_R=0.139	RT	G_RT=232	v_RT=0.43
T	E_T=594	f_c,T=2.67	f_t,T=2.67	α_T=0.255	RL	G_RT=967	v_RL=0.03
L	E_R=12 888	f_c,L=36.25	f_t,L=36.25	α_L=0.019	TL	G_RT=773	v_TL=0.02

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