喀斯特地区马尾松人工林根系抗拉与抗折的力学特性
Tensile and Flexural Properties of Single Roots of Pinus Massoniana in Karst Regions
张晨 1彭语童 1张建利 1杨涛 1古宇航 1溥丽华 1曹阳 2赵卫权2
作者信息
- 1. 贵州民族大学生态环境工程学院,贵州贵阳 550025
- 2. 贵州省山地资源研究所,贵州贵阳 550001
- 折叠
摘要
[目的]探究马尾松(Pinus massoniana)根系抗拉、抗折力学特性和应力—应变特征,充实乔木根系力学特性,以期为马尾松种植区固持土壤、防治水土流失提供参考.[方法]以马尾松0～1,1～2,2～3,3～4,＞4 mm根径根系为研究对象,使用STS5000万能拉力机进行单根试验,分析不同根径根系马尾松抗拉与抗折力学特性及应力—应变特征.[结果]马尾松单根抗拉力和单根抗折力随根径增加均符合y=ax3+bx2+cx+d方程,R2分别为0.91,0.69;抗拉强度和抗折强度随根径增加均符合y-ax-b方程,R2分别为0.50,0.35;根系抗拉延伸率、根系抗拉弹性模量和根系抗折弹性模量随根径增加均符合y=ax3+bx2+cx+d方程,R2分别为0.17,0.22,0.18;根系抗折延伸率与根系径级无明显相关性;马尾松根系抗拉与抗折"应力—应变"曲线表现出弹性变形、弹塑性变形、应变硬化及断裂破坏4个阶段,抗拉"应力—应变"曲线和抗折"应力—应变"曲线在弹塑性变形阶段有不同的变化趋势;抗拉与抗折断裂阶段有周皮断裂与整体断裂两种断裂模式,两种断裂模式受根系周皮与维管组织影响均有两种断裂类型.[结论]马尾松＜3 mm根径根系抗折力学性能优于抗拉力学性能,＞3 mm根系根径抗拉力学性能优于抗折力学性能.马尾松种植于坡面等地区可以有效增强土壤的抗蚀能力.
Abstract
[Objective]The tensile and flexion mechanical properties and stress-strain characteristics of roots of Pinus massoniana were studied to enrich the mechanical properties of tree roots,in order to provide a reference for soil stabilization and soil erosion prevention in planting areas of Pinus massoniana.[Methods]The 0-1,1-2,2-3,3-4 and＞4 mm root diameter roots of Pinus massoniana were taken as the research object.STS5000 universal tensile machine was used to conduct single root test to analyze the tensile and flexion mechanical properties and stress-strain characteristics of different root diameter roots of Pinus massoniana.[Results]Both the tensile strength and flexural strength of a single root of Pinus massoniana increased with increasing root diameter in accordance with the polynomial relationship of y=ax3+bx2+cx+d,having respective R2 values of 0.91 and 0.69.Both the tensile strength and flexural strength decreased with the increasing root diameter according to y=ax-b,having respective R2 values of 0.50 and 0.35.The root tensile elongation rate increased with increasing root diameter according to the equation y=ax3+bx2+cx+d(R2=0.17),while the root flexural elongation rate had no significant correlation with increasing root diameter.Both the tensile elastic modulus and flexural elastic modulus of the root system decreased with increasing root diameter according to y=ax3+bx2+cx+d,having respective R2 values of 0.22 and 0.18.The root tensile and flexural stress-strain curves of Pinus massoniana showed four stages:elastic deformation,elastic-plastic deformation,strain hardening,and peripheral(fracture)failure.The tensile stress-strain curve generally showed an"upward convex"shape,while the bending stress-strain curve generally showed a"downward concave"shape.The tensile and flexural fracture stages were divided into peripheral fracture and overall fracture modes,both of which were influenced by the peripheral and vascular tissues and had two types of fracture.[Conclusion]The flexural mechanical properties of the root system of Pinus massoniana with a root diameter of＜3 mm were superior to the tensile mechanical properties,while the tensile mechanical properties of roots with diameters of＞3 mm were superior to the flexural mechanical properties.Planting Pinus massoniana in slope areas can effectively increase soil erosion resistance.
关键词
喀斯特地区/抗拉力学特性/抗折力学特性/弹性模量/应力—应变特征Key words
karst area/tensile mechanical properties/flexural mechanical properties/elastic modulus/stress-strain characteristics引用本文复制引用
基金项目
贵州省科技计划项目(黔科合支撑[2021]一般460号)
贵州省科技计划项目(黔科合支撑[2022]一般200号)
贵州省科技计划项目(黔科合支撑[2023]一般151号)
贵州科学院省级科研专项(黔科院科专合字[2023]03号)
贵州科学院创新产业研究启动基金(黔科院C字[2021]1号)
贵州省科学技术基金项目(黔科合基础ZK[2023]一般157)
贵州民族大学科研基金项目(2022YB13)
出版年
2024
国家科技期刊平台
NSTL
万方数据