摘要
通过试验研究不同直径玻璃纤维增强复合材料（GFRP）的力学性能,并采用基于材料强度Weibull分布的最弱链理论分析其尺寸效应.试验结果表明,GFRP筋极限抗拉强度、抗拉弹性模量和极限延伸率随着直径增大而下降,而屈服应变变化规律则相反.通过试验分析,建立考虑直径变化的GFRP筋应力应变关系及其相关参数同直径的关系;提出了不同直径GFRP筋极限抗拉强度fDtu计算公式.基于最弱链理论分析,得出GFRP筋尺寸效应的主要影响因素是试件的有效区体积.研究表明,GFRP筋拉伸力学性能具有明显的尺寸效应;采用最弱链理论进行尺寸效应分析是可行的,能够预测不同GFRP筋强度,确定其抗拉强度标准值,有助于统一GFRP筋试件的有效长度取用标准,并建议长度范围为试件直径的30~40倍.
The mechanical properties of GFRP rebars with different diameters were studied experimentally, and the weakest link theory, which is based on the Weibull distribution of material strength, was used to analyze the size effect. The experimental results indicate that the ultimate tensile strength, tensile modulus of elasticity and ultimate elongation percentage decrease as the diameter increases, while the change of the yield strain is the reverse. According to the experimental analysis, the stress-strain relationship of GFRP rebars, taking the diameter variety into account, and the relationship between relevant parameters and diameter were developed. Simultaneously, a formula to calculate the ultimate tensile strength fDtu of GFRP rebars with different diameters was presented. Based on the analysis using weakest link theory, it is presented that the main contributing factor of the size effect of GFRP rebar is the volume of effective region. The size effect on tensile mechanical properties of GFRP rebar is obvious and can be analyzed using weakest link theory. The strength of different GFRP rebars can be predicted as well as the standard value of strength, which will help standardize the effective length of GFRP specimens. The recommended effective length of specimen was 30 to 40 times the diameter of GFRP rebar.
出处
《河海大学学报（自然科学版）》
CAS
CSCD
北大核心
2008年第2期242-247,共6页
Journal of Hohai University(Natural Sciences)
基金
广东省交通科技项目(2004-17)
