Mechanical Analysis of Fiber Glass Reinforced Bonded Flexible Pipe Under External Pressure

2019 ◽  
Author(s):  
Xiaojie Zhang ◽  
Yong Bai ◽  
Chang Liu ◽  
Zhao Wang ◽  
Jiannan Zhao
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Method ◽  
Cross Section ◽  
Mechanical Analysis ◽  
External Pressure ◽  
Fiber Glass ◽  
Flexible Pipe ◽  
Pressure Test ◽  
Element Method

Abstract Fiber glass reinforced bonded flexible pipe (FGRFP) is one kind of new type composite pipe. However, the mechanical properties of FGRFP are not so clearly at present. Therefore, this article aims at studying the buckling pressure of FGRFP under external pressure by using external pressure test, numerical method and finite element method. Three kinds of buckling pressure have been obtained by using three methods as aforesaid. According to compare the buckling pressure of three methods, the relative error of the numerical method and the finite element method relative to external pressure test ranges from 4.09% to 14.51%. According to the result of finite element method, the first layer’s stress at the topside of FGRFP’s cross section and the final layer’s stress at the horizontal position of FGRFP’s cross section is the max stress. The numerical method and finite element method came up with in this article can be used to analyze the buckling pressure of FGRFP. These methods can also provide a guidance to pipeline engineers to design and production of FGRFP.

scholarly journals Assessment of Rectangular Cavity in Concrete Gravity Retaining Wall using Finite Element Method

2019 ◽  
Vol 8 (4) ◽  
pp. 2656-2661
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Stress Distribution ◽  
Cross Section ◽  
Retaining Wall ◽  
Rectangular Cavity ◽  
Gravity Retaining Wall ◽  
The Cross ◽  
Conditions Of Stability ◽  
Element Method

The design of the Gravity retaining wall (GRW) is a trial and error process. Prevailing conditions of backfill are used to determine the profile of GRW, which proceeds with the selection of provisional dimensions. The optimum section is having factors of safety of stability higher than the allowable values and stresses in the cross-section smaller than permissible. The cross-section is designed to fulfill conditions of stability, subjected to very low stresses. The strength of the material, which is provided in the cross-section remains unutilized. A computer program is developed to find stresses at various locations on the cross-section of GRW using the Finite Element Method (FEM). A discontinuity in the form of a rectangular cavity is introduced in the cross-section of GRW to optimize it. The rectangular cavity is introduced in the cross-section of GRW at different locations. An attempt is made in this paper to find the stress distribution in the gravity retaining wall cross-section and to study the effect of the rectangular cavity on the stress distribution. Two cases representing different locations are considered to study the effect of the cavity. The location of the cavity is distinguished by the parameter w, the effects of cases with varied was 0.2305 (Case-I) and 0.1385 (Case-II) are observed. The cavity, which is provided not only makes the wall structurally efficient but also economically feasible.

scholarly journals An Eulerian finite element method for PDEs in time-dependent domains

2019 ◽  
Vol 53 (2) ◽  
pp. 585-614 ◽  
Author(s):  
Christoph Lehrenfeld ◽  
Maxim Olshanskii
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Finite Difference ◽  
Numerical Method ◽  
Computational Domain ◽  
Physical Domain ◽  
Finite Element Approximations ◽  
Additional Stabilization ◽  
Background Mesh ◽  
Element Method

The paper introduces a new finite element numerical method for the solution of partial differential equations on evolving domains. The approach uses a completely Eulerian description of the domain motion. The physical domain is embedded in a triangulated computational domain and can overlap the time-independent background mesh in an arbitrary way. The numerical method is based on finite difference discretizations of time derivatives and a standard geometrically unfitted finite element method with an additional stabilization term in the spatial domain. The performance and analysis of the method rely on the fundamental extension result in Sobolev spaces for functions defined on bounded domains. This paper includes a complete stability and error analysis, which accounts for discretization errors resulting from finite difference and finite element approximations as well as for geometric errors coming from a possible approximate recovery of the physical domain. Several numerical examples illustrate the theory and demonstrate the practical efficiency of the method.

Variational multi-scale finite element method for the two-phase flow of polymer melt filling process

2019 ◽  
Vol 30 (3) ◽  
pp. 1407-1426 ◽  
Author(s):  
Xuejuan Li ◽  
Ji-Huan He
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Method ◽  
Two Phase Flow ◽  
Polymer Melt ◽  
Phase Flow ◽  
Filling Process ◽  
Two Phase ◽  
Content Type ◽  
Element Method

Purpose The purpose of this paper is to develop an effective numerical algorithm for a gas-melt two-phase flow and use it to simulate a polymer melt filling process. Moreover, the suggested algorithm can deal with the moving interface and discontinuities of unknowns across the interface. Design/methodology/approach The algebraic sub-grid scales-variational multi-scale (ASGS-VMS) finite element method is used to solve the polymer melt filling process. Meanwhile, the time is discretized using the Crank–Nicolson-based split fractional step algorithm to reduce the computational time. The improved level set method is used to capture the melt front interface, and the related equations are discretized by the second-order Taylor–Galerkin scheme in space and the third-order total variation diminishing Runge–Kutta scheme in time. Findings The numerical method is validated by the benchmark problem. Moreover, the viscoelastic polymer melt filling process is investigated in a rectangular cavity. The front interface, pressure field and flow-induced stresses of polymer melt during the filling process are predicted. Overall, this paper presents a VMS method for polymer injection molding. The present numerical method is extremely suitable for two free surface problems. Originality/value For the first time ever, the ASGS-VMS finite element method is performed for the two-phase flow of polymer melt filling process, and an effective numerical method is designed to catch the moving surface.

Sign in / Sign up

Export Citation Format

Share Document