早龄期混凝土分数阶Burgers徐变模型研究

Fractional-Order Burgers Creep Model for Concrete Under Early Age Period

早龄期混凝土徐变对工程结构体安全设计至关重要,研究针对早龄期混凝土徐变是控制和保证混凝土工程安全施工和正常运行的关键.基于粘弹塑性流变理论、Riemann-Liouville理论和Burgers组合模型理论,利用Able粘壶重构分数阶软体组合元件,提出分数阶Burgers模型的应力-应变关系表达式,构建基于分数微积分理论的早龄期混凝土徐变本构模型.通过早龄期混凝土压缩徐变试验数据进行验证,所构建模型能够对早龄期混凝土徐变过程保持较高的一致性,并通过分数阶阶数n的敏感性分析,可以实现对实际工程中早龄期混凝土徐变程度的有效控制.基于分数阶的Burgers模型可为早龄期混凝土徐变模型提供一种新的思路.

Early age concrete creep is very important for the safety design of engineering structures.Research on early age concrete creep is the key to control and ensure the safe construction and normal operation of concrete projects.Based on viscoelastic-plastic rheological theory,Riemann-Liouville theory and Burgers combined model theory,fractional-order software components are reconstructed by Able viscous pot.The stress-strain relationship expression of fractional-order Burgers model is proposed,and the creep constitutive model of early-age concrete based on fractional calculus theory is constructed.Through the verification of the compression and creep test data of the early age concrete,the model can maintain a high consistency in the creep process of the early age concrete.Through the sensitivity analysis of fractional order n,the effective control of the creep degree of the early age concrete in the actual project can be realized.The Burgers model based on fractional order can provide a new idea for the early age concrete creep model.