西安建筑科技大学学报(自然科学版)

不同使用年限的柏木基本材料力学性能试验对比研究

刘德贵¹,陈科材²,邓云毅¹,李建春¹

(1.西南科技大学土木工程与建筑学院,四川绵阳 621010; 2.宜宾市公路局,四川宜宾 644000; 3.石榴置业集团股份有限公司,北京 102488)

Experimental study of the influence of service time on the basic material mechanical properties of cedar-wood

LIU Degui¹,CHEN Kecai²,DENG Yunyi¹,LI Jianchun¹

(1.School of Civil Engineering and Architecture, Southwest University of Science and Technology, Mianyang 621010, China; 2.Yibin Highway Bureau, Yinbin 644000, China; 3.Pomegranate Real Estate Group Co.Ltd.,Beijing 102488, China)

Keywords： cedar-wood; compression strength; tensile strength; bending tensile strength; bending elasticity modulus

DOI: 10.15986-j.1006-7930.2019.06.011

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摘要

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参考文献

木材的抗压、抗拉、抗弯强度等基本力学性能指标受环境温度、湿度等因素影响,最终表现为随使用时间而变化,而基本力学性能指标随时间的变化将对木结构的全寿命周期内的结构受力性能产生影响.为此,通过调研收集了4种不同使用年限(时间)的木结构建筑使用过的柏木,对这些柏木进行了抗压、抗拉和抗弯性能试验,获取了不同使用年限(时间)柏木的抗压强度、抗拉强度和弯曲抗拉强度及弹性模量等力学性能指标,探讨了柏木随使用时间年限的增长,其基本力学性能指标的变化,分析了上述力学性能指标随时间变化的规律.试验结果表明,柏木顺纹抗压强度随使用年限的增长而逐渐降低,使用年限越长,降低越明显; 柏木顺纹抗拉强度、弯曲抗拉强度和抗弯弹性模量早期都表现出一定的增长,到一定年限(本试验为10 a)达到最大值,然后随使用年限的增长而逐渐降低; 随使用年限增长,柏木会表现出明显的脆性.柏木等木材随使用时间增长其力学性能的变化应在木结构的全寿命周期受力性能的研究中引起重视.

The basic mechanical properties,such as the compression strength,tensile strength and bending strength of wood, will be affected by temperature and humidity etc, it finally show that the mechanical properties influenced by the time.Therefore, with the increase of service time,the mechanical behavior of wood structure in the Total Life Cycle would be influenced by the changing of the mechanical properties indexes.In this paper, four different service time cedar-wood were collected by investigation, and the compression, tensile and bending tests were conducted for the four different service time cedar-wood. The compression strength, tensile strength, bending tensile strength and bending elasticity modulus were obtained for the four different service time cedar-wood, and the regulation were discussed and analyzed for that the compression strength, tensile strength, bending tensile strength and bending elasticity modulus were changed by the increase of the service time. These tests results show that the compression strength decreases gradually with the increase of service time, and the longer the service time is, the more obvious the decrease is; the tensile strength, compression tensile strength and bending elasticity modulus of cedar-wood show a certain increase in the early stage, reaching the maximum value in a certain period of time(this test is 10 years), and then declining with the increase of service time; and the cedar-wood show obvious brittleness with the increase of the service time. The phenomenon that mechanical properties of wood, such as cedar-wood, are changed with the increase of service time should be paid more attention in the study of the mechanical properties of wood structures in the Total Life Cycle.

引言
1 试验材料
2 柏木顺纹抗压试验
3 柏木顺纹抗拉试验
4 柏木弯曲抗拉强度试验
5 结论

图1 试验木材
Fig.1 The test wood

图2 柏木含水率试样<br/>Fig.2 Specimen of test determination for moisture ofcedar-wood

图2 柏木含水率试样
Fig.2 Specimen of test determination for moisture ofcedar-wood

图3 柏木含水率试验<br/>Fig.3 Test determination for moisture of cedar-wood

图3 柏木含水率试验
Fig.3 Test determination for moisture of cedar-wood

图4 抗压试验试块<br/>Fig.4 Test specimen for determination compressive strength parallel to grain of wood

图4 抗压试验试块
Fig.4 Test specimen for determination compressive strength parallel to grain of wood

图5 柏木抗压试验<br/>Fig.5 Test determinationcompressive strength of cedar-wood

图5 柏木抗压试验
Fig.5 Test determinationcompressive strength of cedar-wood

图6 抗压试验试样典型破坏形态<br/>Fig.6 Typical failure mode of compression test specimen

图6 抗压试验试样典型破坏形态
Fig.6 Typical failure mode of compression test specimen

图7 不同使用年限柏木代表性抗压试验荷载 - 位移曲线<br/>Fig.7 Load-displacement curve of typical compressive test for cedar-wood with different service life

图7 不同使用年限柏木代表性抗压试验荷载 - 位移曲线
Fig.7 Load-displacement curve of typical compressive test for cedar-wood with different service life

表1 不同使用年限柏木的抗压强度<br/>Tab.1 Compressive strength of cedar-wood with different service life MPa

表1 不同使用年限柏木的抗压强度
Tab.1 Compressive strength of cedar-wood with different service life MPa

图8 不同使用年限柏木抗压强度值<br/>Fig.8 Compressive strength of cedar-wood with different service life

图8 不同使用年限柏木抗压强度值
Fig.8 Compressive strength of cedar-wood with different service life

图9 抗拉试验试件<br/>Fig.9 Test specimen for determination tensile strength

图9 抗拉试验试件
Fig.9 Test specimen for determination tensile strength

图10 柏木的抗拉试验<br/>Fig.10 Test determination tensile strength of cedar-wood

图10 柏木的抗拉试验
Fig.10 Test determination tensile strength of cedar-wood

图11 抗拉试验典型破坏形态<br/>Fig.11 Typical failure mode of tensile test specimen

图11 抗拉试验典型破坏形态
Fig.11 Typical failure mode of tensile test specimen

图12 不同使用年限柏木代表性抗拉荷载 - 位移曲线<br/>Fig.12 Load-displacement curve of typical tensile test for cedar-wood with different service life

图12 不同使用年限柏木代表性抗拉荷载 - 位移曲线
Fig.12 Load-displacement curve of typical tensile test for cedar-wood with different service life

表2 不同使用年限柏木的抗拉强度<br/>Tab.2 Tensile strength of cedar-wood with different service life MPa

表2 不同使用年限柏木的抗拉强度
Tab.2 Tensile strength of cedar-wood with different service life MPa

图13 不同使用年限柏木的抗拉强度值<br/>Fig.13 Tensile strength of cedar-wood with different service life

图13 不同使用年限柏木的抗拉强度值
Fig.13 Tensile strength of cedar-wood with different service life

图14 抗弯试验试件<br/>Fig.14 Test specimen for determination bending tensile strength

图14 抗弯试验试件
Fig.14 Test specimen for determination bending tensile strength

图15 柏木弯曲抗拉强度试验<br/>Fig.15 Test determination bending tensile strength of cedar-wood

图15 柏木弯曲抗拉强度试验
Fig.15 Test determination bending tensile strength of cedar-wood

图16 柏木抗弯试验典型破坏形态<br/>Fig.16 Typical failure mode of bending tensile test specimen

图16 柏木抗弯试验典型破坏形态
Fig.16 Typical failure mode of bending tensile test specimen

图17 不同使用年限柏木代表性弯曲抗拉试验荷载 - 位移曲线<br/>Fig.17 Load-displacement curve of typical bending tensile test for cedar-wood with different service life

图17 不同使用年限柏木代表性弯曲抗拉试验荷载 - 位移曲线
Fig.17 Load-displacement curve of typical bending tensile test for cedar-wood with different service life

表3 不同使用年限柏木的极限抗弯强度<br/>Tab.3 Bending tensile strength of cedar-wood with different service life MPa

表3 不同使用年限柏木的极限抗弯强度
Tab.3 Bending tensile strength of cedar-wood with different service life MPa

图18 试件的抗弯强度值<br/>Fig.18 Bending tensile strength of cedar-wood with different service life

图18 试件的抗弯强度值
Fig.18 Bending tensile strength of cedar-wood with different service life

表4 柏木的抗弯弹性模量值<br/>Tab.4 Bending elasticity modulus of cedar-wood with different service life MPa

表4 柏木的抗弯弹性模量值
Tab.4 Bending elasticity modulus of cedar-wood with different service life MPa

图19 柏木抗弯弹性模量<br/>Fig.19 Bending elasticity modulus

图19 柏木抗弯弹性模量
Fig.19 Bending elasticity modulus

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期刊信息

西安建筑科技大学学报(自然科学版)
（1957年创刊双月刊）

主管单位：陕西省教育厅

主办单位：西安建筑科技大学

主　　编：刘加平（院士）

副主编：史庆轩（常务）张引科张小龙

国内刊号：CN61-1295/TU

I S S N：1006-7930

地　　址：西安市雁塔路中段13号

国内发行：西安建筑科技大学学报编辑部

国外发行：中国出版对外贸易总公司

编辑出版：西安建筑科技大学学报编辑部

备注

引言

1 试验材料

2 柏木顺纹抗压试验

3 柏木顺纹抗拉试验

4 柏木弯曲抗拉强度试验

5 结论

期刊信息