scholarly journals Numerical Analysis of the Contact Behavior of a Polymer-Based Waterproof Membrane for Tunnel Lining

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2704
Author(s):  
Kicheol Lee ◽  
Dongwook Kim ◽  
Soon-Wook Choi ◽  
Soo-Ho Chang ◽  
Tae-Ho Kang ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Numerical Analysis ◽  
Material Properties ◽  
Interfacial Adhesion ◽  
Laboratory Experiments ◽  
Tunnel Lining ◽  
Contact Conditions ◽  
Contact Behavior ◽  
Initial Strength ◽  
Interface Parameters

Waterproof membranes have higher initial strength, faster construction, and better waterproofing than conventional sheet membranes. In addition, their polymer constituents have much higher interfacial adhesion and tensile strength than those of conventional materials. However, despite their advantages, waterproof membranes are not widely used in civil construction. This study evaluates the material properties and interface parameters of a waterproof membrane by considering the results of laboratory experiments and numerical analysis. Since the contact behavior of a membrane at its interface with shotcrete is important for understanding the mechanism of the support it offers known as a shotcrete tunnel lining, modeling should adopt appropriate contact conditions. The numerical analysis identifies the suitability and contact conditions of the waterproof membrane in various conditions.

Numerical analysis of damage zones in a bridge

2019 ◽  
Vol 11 (1) ◽  
pp. 1-12
Author(s):  
Mohammed Lamine Moussaoui ◽  
Mohamed Chabaat
Keyword(s):  
Numerical Analysis ◽  
Material Properties ◽  
Data File ◽  
Time Range ◽  
Bridge Structure ◽  
Time Step ◽  
Batch Mode ◽  
Content Type ◽  
Finite Element Software ◽  
Von Mises

Purpose The purpose of this paper is to present a numerical analysis of structural monitoring for damage zones detection. The study is performed with Ansys finite element software, which reads in batch mode programming a previously generated mesh data file and computes the transient dynamic solution for each time-step iteration within an analysis time range. Design/methodology/approach The approach itself is applied on a bridge structure which can be potentially subjected to damage zones due to severe loads cases and or earthquakes vibrations. The ideal Von Mises failure criterion ellipsoid envelope is applied for the detection of overstepped computed stresses and strains. Findings This numerical analysis allows computing, for each time-step iteration, the dynamic displacements at each degree of freedom and the corresponding stresses and strains inside the elements under the action of several times dependent loads cases. Practical implications Several simulations are considered to quantify the external loads. Originality/value The material properties of reinforced concrete RC are calculated for an existing specific bridge structure case. The RC strength is then introduced from the basic compounds material properties using the corresponding volumes fractions.

An Approach to Determine the Stiffness Reduction Factor of Tunnel Lining

2011 ◽  
Vol 243-249 ◽  
pp. 3659-3662
Author(s):  
Hai Ying Zhou ◽  
Li Xin Li ◽  
Ting Guo Chen
Keyword(s):  
Numerical Analysis ◽  
Flexural Rigidity ◽  
Resistance Coefficient ◽  
Reduction Factor ◽  
Tunnel Lining ◽  
Soil Resistance ◽  
Stiffness Reduction ◽  
Simplified Method

Based on the segmental joint tests, it was found that the practical range of joint flexural rigidity was in range of 8500-29000kN•m/rad. A simplified method for determining the stiffness reduction factor of tunnel lining() was proposed using results from the segmental joint tests in which some parameters were obtained by calibration against a 3D Numerical analysis. The influence of joint flexural rigidity, soil resistance coefficient, thickness of tunnel lining and tunnel calculation radius on the stiffness reduction factor of tunnel lining was examined. The stiffness reduction factor can be simply expressed as a function of joint flexural rigidity ratio, soil resistance coefficient, thickness of tunnel lining and tunnel calculation radius for the typical tunnel lining.

Investigation of Contact Conditions During Stamping of a Thin Plate

2020 ◽  
Author(s):  
Harshal Y. Shahare ◽  
Rohan Rajput ◽  
Puneet Tandon
Keyword(s):  
Wave Propagation ◽  
Material Properties ◽  
High Speed ◽  
Fdtd Method ◽  
Propagation Model ◽  
Transmitted Wave ◽  
Two Dimensional ◽  
Contact Conditions ◽  
Simulation Based ◽  
Difference Time

Abstract Stamping is one of the most used manufacturing processes, where real-time monitoring is quite difficult due to high speed of the mechanical press, which leads to deterioration of the accuracy of the products In the present work, a method is developed to model elastic waves propagation in solids to measure contact conditions between die and workpiece during stamping. A two-dimensional model is developed that reduces the wave propagation equations to two-dimensional equations. To simulate the wave propagation inside the die-workpiece model, the finite difference time domain (FDTD) method and modified Yee algorithm has been employed. The numerical stability of the wave propagation model is achieved through courant stability condition, i.e., Courant-Friedrichs-Lewy (CFL) number. Two cases, i.e., flat die-workpiece interface and inclined die-workpiece interface, are investigated in the present work. The elastic wave propagation is simulated with a two-dimension (2D) model of the die and workpiece using reflecting boundary conditions for different material properties. The experimental and simulation-based results of reflected and transmitted wave characteristics are compared for different materials in terms of reflected and transmitted wave height ratio and material properties such as acoustic impedance. It is found that the numerical simulation results are in good agreement with the experimental results.

scholarly journals Determination of the Material Properties of the Reinforcement for Textile-Reinforced Concrete Elements

2021 ◽  
Author(s):  
Sergej Rempel ◽  
Marcus Ricker ◽  
Tânia Feiri
Keyword(s):  
Tensile Strength ◽  
Reinforced Concrete ◽  
Tensile Test ◽  
Material Properties ◽  
Construction Material ◽  
Gumbel Distribution ◽  
Mean Value ◽  
Elastic Behaviour ◽  
Textile Reinforced Concrete ◽  
Design Values

Abstract Textile-reinforced concrete has emerged in recent years as a new and valuable construction material. The design of textile-reinforced concrete requires knowledge on the mechanical properties of different textile types as well as their reinforcing behaviour under different loading conditions. Conventional load-bearing tests tend to be complex, time-consuming, costly and can even lack consistent specifications. To mitigate such drawbacks, a standardised tensile test for fibre strands was developed aiming at characterising the material properties needed for the design of a textile-reinforced concrete component. For the sake of this study, an epoxy resin-soaked AR-glass reinforcement was considered. The standardised tensile test uses a fibre strand with 160 mm length, which shall be cut out of a textile grid. The results show that the textile reinforcement has a linear-elastic behaviour, and the ultimate tensile strength can be statistically modelled by a Gumbel distribution. Furthermore, the results indicate that the modulus of elasticity is not influenced by the length or the number of fibre strands. Therefore, the mean value from the standardised test can be used for the design purpose. These findings are essential to derive an appropriate partial safety factor for the calculation of the design values of the tensile strength and can be used to determine the failure probability of textile-reinforced concrete components.

scholarly journals Reduction of Dynamic Impacts in Block Made of Concrete - Rubber Composites

2018 ◽  
Vol 14 (1) ◽  
pp. 61-68 ◽  
Author(s):  
Maciej Major ◽  
Izabela Major ◽  
Daniela Kuchárová ◽  
Krzysztof Kuliński
Keyword(s):  
Numerical Analysis ◽  
Dynamic Load ◽  
Material Properties ◽  
Material Model ◽  
Damping Factor ◽  
Rubber Composites ◽  
Elastic Deformations ◽  
Real Material ◽  
Additional Protection ◽  
Rubber Concrete

AbstractThe paper presents numerical analysis of block made of three layers: concrete with I-shape rubber pads, space filled with air and concrete with embedded cross rubber pads, respectively. The block is subjected to the dynamic load. To the analysis as rubber the hyperelastic incompressible Zahorski material model was assumed. This material well describes the real material properties in the range of large elastic deformations. Embedded rubber pads provide an additional protection against the transversal dynamic load. ADINA software was utilized to perform numerical analysis of determining the percentage damping factor of rubber-concrete composite in comparison with block made of concrete.

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