水浸时效对红锥木材蠕变特性的影响
The Influence of Water Immersion Aging on Creep Characteristics of Castanopsis hystrix Wood

采用4点加载方式分别对红锥自然气干试材及水浸时效试验材料进行短时间(420 min)弯曲蠕变试验，获取红锥木材在2种不同时效状态下的弯曲蠕变特性常数，分析2种时效状态下红锥的蠕变性能，并对水浸时效对红锥蠕变性能的改善效果作出评价。结果表明，在弯曲应力为σb？？40%的荷载下，红锥自然气干材的蠕变特性常数J0为8.408×10-7cm2/N、η0为436.293×10-7min N/cm2、∑Ji为0.784×10-7cm2/N；红锥水浸时效材的蠕变特性常数J0为7.752×10-7cm2/N、η0为502.000×10-7min N/cm2、∑Ji为0.341×10-7cm2/N。红锥木材经水浸时效处理后，其瞬间弹性柔量J0及延迟弹性柔量∑Ji均较气干材有所降低，而粘性系数η0则较气干材有较大幅度的提高。说明红锥木材经水浸时效处理后其抗瞬间弹性变形能力、抗延迟弹性变形能力及抗长期粘性变形的能力得到增强。
By means of the four-point loading, a short time (420 min) bending creep testing on air-dried wood samples and water immersion aging samples of Castanopsis hystrix were respectively carried out to obtain the bending creep characteristic constants of the woods under two different aging states, and to analyze their creep properties under two different aging states, also to evaluate the improvement effect of the creep properties after water immersion aging. Experimental results showed that when the load of bending stress was under 40% of tensile strength, constants J0, η0, and ∑Ji of creep properties of air-dried wood sample were 8.408×10-7cm2/N, 436.293×10-7min N/cm2, and 0.784×10-7cm2/N, respectively. While after the wood had been immersed in water, the constants of J0, η0, and ∑Ji were 7.752×10-7 cm2/N, 502.000×10-7 min N/cm2, and 0.341×10-7 cm2/N, respectively. The conclusions were that comparing with air-dried wood, after the wood had been immersed in water with aging treatment, both of instantaneous elastic compliance J0 and delayed elastic compliance ∑Ji were lower than the constants of the air dried wood, but the resistance of viscous coefficient had been significantly improved comparing with the air-dried wood. It showed that after the immersed treatment in water, the resistance abilities of instantaneous elastic deformation, delayed elastic deformation and long time viscous deformation were improved