Orthotropic nonlinear elastic materials are common in nature and widely used by various industries.However,there are only limited constitutive models available in today's commercial software(e.g.,ABAQUS,ANSYS,etc....Orthotropic nonlinear elastic materials are common in nature and widely used by various industries.However,there are only limited constitutive models available in today's commercial software(e.g.,ABAQUS,ANSYS,etc.)that adequately describe their mechanical behavior.Moreover,the material parameters in these constitutive models are also difficult to calibrate through low-cost,widely available experimental setups.Therefore,it is paramount to develop new ways to model orthotropic nonlinear elastic materials.In this work,a data-driven orthotropic nonlinear elastic(DDONE)approach is proposed,which builds the constitutive response from stress–strain data sets obtained from three designed uniaxial tensile experiments.The DDONE approach is then embedded into a finite element(FE)analysis framework to solve boundary-value problems(BVPs).Illustrative examples(e.g.,structures with an orthotropic nonlinear elastic material)are presented,which agree well with the simulation results based on the reference material model.The DDONE approach generally makes accurate predictions,but it may lose accuracy when certain stress–strain states that appear in the engineering structure depart significantly from those covered in the data sets.Our DDONE approach is thus further strengthened by a mapping function,which is verified by additional numerical examples that demonstrate the effectiveness of our modified approach.Moreover,artificial neural networks(ANNs)are employed to further improve the computational efficiency and stability of the proposed DDONE approach.展开更多
The nonlinear dynamic characteristics of a pile embedded in a rock were investigated. Suppose that both the materials of the pile and the soil around the pile obey nonlinear elastic and linear viscoelastic constitutiv...The nonlinear dynamic characteristics of a pile embedded in a rock were investigated. Suppose that both the materials of the pile and the soil around the pile obey nonlinear elastic and linear viscoelastic constitutive relations. The nonlinear partial differential equation governing the dynamic characteristics of the pile was first derived. The Galerkin method was used to simplify the equation and to obtain a nonlinear ordinary differential equation. The methods in nonlinear dynamics were employed to solve the simplified dynamical system, and the time-path curves, phase-trajectory diagrams, power spectrum, Poincare sections and bifurcation and chaos diagrams of the motion of the pile were obtained. The effects of parameters on the dynamic characteristics of the system were also considered in detail.展开更多
基金The support of Project MKF20210033 is acknowledged.
文摘Orthotropic nonlinear elastic materials are common in nature and widely used by various industries.However,there are only limited constitutive models available in today's commercial software(e.g.,ABAQUS,ANSYS,etc.)that adequately describe their mechanical behavior.Moreover,the material parameters in these constitutive models are also difficult to calibrate through low-cost,widely available experimental setups.Therefore,it is paramount to develop new ways to model orthotropic nonlinear elastic materials.In this work,a data-driven orthotropic nonlinear elastic(DDONE)approach is proposed,which builds the constitutive response from stress–strain data sets obtained from three designed uniaxial tensile experiments.The DDONE approach is then embedded into a finite element(FE)analysis framework to solve boundary-value problems(BVPs).Illustrative examples(e.g.,structures with an orthotropic nonlinear elastic material)are presented,which agree well with the simulation results based on the reference material model.The DDONE approach generally makes accurate predictions,but it may lose accuracy when certain stress–strain states that appear in the engineering structure depart significantly from those covered in the data sets.Our DDONE approach is thus further strengthened by a mapping function,which is verified by additional numerical examples that demonstrate the effectiveness of our modified approach.Moreover,artificial neural networks(ANNs)are employed to further improve the computational efficiency and stability of the proposed DDONE approach.
基金Project supported by the National Natural Science Foundation of China （Grant No.50278051）, and the Shanghai Leading Academic Discipline Project （Grant No.Y0103）
文摘The nonlinear dynamic characteristics of a pile embedded in a rock were investigated. Suppose that both the materials of the pile and the soil around the pile obey nonlinear elastic and linear viscoelastic constitutive relations. The nonlinear partial differential equation governing the dynamic characteristics of the pile was first derived. The Galerkin method was used to simplify the equation and to obtain a nonlinear ordinary differential equation. The methods in nonlinear dynamics were employed to solve the simplified dynamical system, and the time-path curves, phase-trajectory diagrams, power spectrum, Poincare sections and bifurcation and chaos diagrams of the motion of the pile were obtained. The effects of parameters on the dynamic characteristics of the system were also considered in detail.
