钢纤维砼复合梁有限元建模的可行性分析  

Feasibility Analysis of Finite Element Modeling of Steel Fiber Reinforced Concrete Composite Beam

作　　者：孙健 SUN Jian(Sichuan Tibetan Expressway Co.,Ltd.,Chengdu 610000,China)

机构地区：[1]四川藏区高速公路有限责任公司,四川成都610000

出　　处：《工业技术创新》2022年第6期58-66,共9页Industrial Technology Innovation

摘　　要：钢纤维砼作为一种混合型混凝土基体,在应用于梁结构时具有良好的阻裂效果,但其开裂、破坏机理的表达是有限元建模中的难点。构建通用的混凝土塑性损伤模型,根据Sidoroff能量等效原理,考虑混凝土塑性损伤特性,推导典型的混凝土塑性损伤因子,明确钢纤维砼的塑性本构参数,得到了容易迭代收敛、数值贴合实际情况的钢纤维砼单轴非弹性应力—应变曲线。建立有限元模型,考察钢纤维砼复合梁的开裂特征和承载力,并利用随机函数开展分离式建模,论证钢纤维砼复合梁有限元建模的可行性与适用性。研究发现:建立的有限元模型可以在后处理分析功能中考察具有不同钢纤维砼厚度的梁结构的开裂、破坏情况,对钢纤维砼复合梁进行准确、可靠的模拟;在钢纤维数量不多的特定小梁结构中,可随机生成实现一定数量的钢纤维,实现分离式建模,更加直观地了解钢纤维的应力变化。As a kind of mixed concrete matrix,steel fiber reinforced concrete has a good crack resistance effect when applied to beam structures,but the expression of its cracking and failure mechanism is a difficult point in finite element modeling.A general plastic damage model of concrete was constructed.According to the Sidoroff energy equivalence principle and considering the plastic damage characteristics of concrete,typical plastic damage factors of concrete were deduced,and the plastic constitutive parameters of steel fiber reinforced concrete were defined.The uniaxial inelastic stress-strain curve of steel fiber reinforced concrete which is easy to be iteratively converged and whose numerical value fits the actual situation was obtained.The finite element model was established,the cracking characteristics and bearing capacity of steel fiber reinforced concrete composite beams were investigated,and the separate modeling using random function was carried out,as to demonstrate the feasibility and applicability of finite element modeling of steel fiber reinforced concrete composite beams.It is found out that the established finite element model can be used in post-processing analysis to investigate the cracking and damage of beam structures with different thickness of steel fiber reinforced concrete,and to realize accurately and reliably simulation of steel fiber reinforced concrete composite beams.In a specific trabecular structure with a small number of steel fibers,a certain number of steel fibers can be randomly generated,so that the separated modeling can be realized,and the stress changes of steel fibers can be more intuitively understandable.

关 键 词：塑性损伤 钢纤维砼复合梁 有限元建模 随机分布 分离式建模 

分 类 号：TU375.1[建筑科学—结构工程]