scholarly journals Mechanical Response of Typical Cement Concrete Pavements under Impact Loading

2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Ding Fei ◽  
Yin Yan ◽  
Cai Liangcai ◽  
Tang Yaohong ◽  
Wang Xuancang
Keyword(s):  
Finite Element ◽  
Impact Loading ◽  
Mechanical Response ◽  
Impact Load ◽  
Damage Model ◽  
Three Dimensional ◽  
Element Model ◽  
Concrete Pavements ◽  
Cement Concrete ◽  
Concrete Damage

In order to study the mechanical response of cement concrete pavements under impact loading, four types of typical cement concrete pavement structures are investigated experimentally and numerically under an impact load. Full-scale three-dimensional pavement slots are tested under an impact load and are monitored for the mechanical characteristics including the deflection of the pavement surface layer, the strain distribution at the bottom of the slab, and the plastic damage and cracking under the dynamic impact load. Numerical analysis is performed by developing a three-dimensional finite element model and by utilizing a cement concrete damage model. The results show that the calculation results based on the cement concrete damage model are in reasonable agreement with the experimental results based on the three-dimensional test slot experiment. The peak values of stress and strain as monitored by the sensors are analyzed and compared with the numerical results, indicating that the errors of numerical results from the proposed model are mostly within 10%. The rationality of the finite element model is verified, and the model is expected to be a suitable reference for the analysis and design of cement concrete pavements.

Experimental Characterization and Finite Element Modeling of Film Capacitors for Automotive Applications

2016 ◽  
Author(s):  
D. Croccolo ◽  
T. M. Brugo ◽  
M. De Agostinis ◽  
S. Fini ◽  
G. Olmi
Keyword(s):  
Finite Element ◽  
Mechanical Response ◽  
High Reliability ◽  
Three Dimensional ◽  
Strain Analysis ◽  
Life Time ◽  
Element Model ◽  
Image Correlation ◽  
Thermal Loads ◽  
Mechanical Shock

As electronics keeps on its trend towards miniaturization, increased functionality and connectivity, the need for improved reliability capacitors is growing rapidly in several industrial compartments, such as automotive, medical, aerospace and military. Particularly, recent developments of the automotive compartment, mostly due to changes in standards and regulations, are challenging the capabilities of capacitors in general, and especially film capacitors. Among the required features for a modern capacitor are the following: (i) high reliability under mechanical shock, (ii) wide working temperature range, (iii) high insulation resistance, (iv) small dimensions, (v) long expected life time and (vi) high peak withstanding voltage. This work aims at analyzing the key features that characterize the mechanical response of the capacitor towards temperature changes. Firstly, all the key components of the capacitor have been characterized, in terms of strength and stiffness, as a function of temperature. These objectives have been accomplished by means of several strain analysis methods, such as strain gauges, digital image correlation (DIC) or dynamic mechanical analysis (DMA). All the materials used to manufacture the capacitor, have been characterized, at least, with respect to their Young’s modulus and Poisson’s ratio. Then, a three-dimensional finite element model of the whole capacitor has been set up using the ANSYS code. Based on all the previously collected rehological data, the numerical model allowed to simulate the response in terms of stress and strain of each of the capacitor components when a steady state thermal load is applied. Due to noticeable differences between the thermal expansion coefficients of the capacitor components, stresses and strains build up, especially at the interface between different components, when thermal loads are applied to the assembly. Therefore, the final aim of these numerical analyses is to allow the design engineer to define structural optimization strategies, aimed at reducing the mechanical stresses on the capacitor components when thermal loads are applied.

A finite element model to study the effect of porosity location on the elastic modulus of a cantilever beam

2019 ◽  
Vol 43 (4) ◽  
pp. 443-453
Author(s):  
Stephen M. Handrigan ◽  
Sam Nakhla
Keyword(s):  
Finite Element ◽  
Elastic Modulus ◽  
Focused Ion Beam ◽  
Mechanical Response ◽  
Ion Beam ◽  
Three Dimensional ◽  
Beam Theory ◽  
Element Model ◽  
Fe Model ◽  
Three Dimensional Finite Element

An investigation to determine the effect of porosity concentration and location on elastic modulus is performed. Due to advancements in testing methods, the manufacturing and testing of microbeams to obtain mechanical response is possible through the use of focused ion beam technology. Meanwhile, rigorous analysis is required to enable accurate extraction of the elastic modulus from test data. First, a one-dimensional investigation with beam theory, Euler–Bernoulli and Timoshenko, was performed to estimate the modulus based on load-deflection curve. Second, a three-dimensional finite element (FE) model in Abaqus was developed to identify the effect of porosity concentration. Furthermore, the current work provided an accurate procedure to enable accurate extraction of the elastic modulus from load-deflection data. The use of macromodels such as beam theory and three-dimensional FE model enabled enhanced understanding of the effect of porosity on modulus.

THE EFFECT OF SHEAR REINFORCEMENT RATIO ON PRESTRESSED CONCRETE BEAMS SUBJECTED TO IMPACT LOAD

2018 ◽  
Vol 5 (1) ◽  
Author(s):  
Mohamad Elani ◽  
Yehya Temsah ◽  
Hassan Ghanem ◽  
Ali Jahami ◽  
Youmn Al Rawi
Keyword(s):  
Finite Element ◽  
Prestressed Concrete ◽  
Impact Load ◽  
Nonlinear Behavior ◽  
Element Model ◽  
Shear Reinforcement ◽  
Dynamic Increase Factor ◽  
Concrete Damage ◽  
Different Response ◽  
The Impact

Structural elements subjected to impact loads have a different response than those subjected to static loads. This research studied the effect of using shear reinforcement to reduce the local damage occurred when an impact load applied on a prestressed concrete beam. An accurate finite element model was provided for the analysis using the advanced volumetric finite element modeling program (ABAQUS). The concrete material was defined using the built in concrete damage plasticity model (CDP), that considers the nonlinear behavior of concrete when subjected to dynamic loading. All material properties were modified using the dynamic increase factor (DIF) to consider the effect of impact loading. It was realized that the failure was concentrated in the impact zone. However, using shear reinforcement reduced the permanent damage occurred due to impact.

Research on Load Transfer Efficiency of GFRP Dowel in Jointed Plain Concrete Pavement

2012 ◽  
Vol 178-181 ◽  
pp. 1152-1155 ◽  
Author(s):  
Luo Ke Li ◽  
Yun Liang Li ◽  
Yi Qiu Tan ◽  
Zhong Jun Xue
Keyword(s):  
Finite Element ◽  
Load Transfer ◽  
Concrete Slab ◽  
Three Dimensional ◽  
Plain Concrete ◽  
Element Model ◽  
Transfer Efficiency ◽  
Engineering Practice ◽  
Concrete Pavements ◽  
Load Transfer Efficiency

In a jointed plain concrete pavements, the dowel bar system are used to provide lateral load transfer across transverse joint. Corrosion of commonly used steel dowel in engineering practice reduces their service life and costs considerable maintenance and repair spending for concrete pavements. The objective of this study focus primarily on the performance of none eroded GFRP dowel on LTE( load transfer efficiency) with the help of a three-dimensional finite-element model. The amount of LTE can be obtained directly from comparing the maximum deflection of the concrete slab and the level tensile stress under the concrete slab. According to the finite element results, the larger-diameter GFRP dowel are found to perform the best in this study.

Transient Thermal Analysis and Viscoplastic Damage Model for Life Prediction of Turbine Components

2014 ◽  
Vol 137 (4) ◽  
Author(s):  
A. Staroselsky ◽  
T. J. Martin ◽  
B. Cassenti
Keyword(s):  
Finite Element ◽  
Life Prediction ◽  
Failure Modes ◽  
Damage Model ◽  
High Stress ◽  
Three Dimensional ◽  
Element Model ◽  
Dissipated Energy ◽  
Transient Thermal ◽  
Turbine Airfoils

This paper reports the process and computer methodology for a physics-based prediction of overall deformation and local failure modes in cooled turbine airfoils, blade outer air seals, and other turbomachinery parts operating in severe high temperature and high stress environments. The computational analysis work incorporated time-accurate, coupled aerothermal computational fluid dynamics (CFD) with nonlinear deformation thermal-structural finite element model (FEM) with a slip-based constitutive model, evaluated at real engine characteristic mission times, and flight points for part life prediction. The methodology utilizes a fully coupled elastic-viscoplastic model that was based on crystal morphology, and a semi-empirical life prediction model introduced the use of dissipated energy to estimate the remaining part life in terms of cycles to failure. The method was effective for use with three-dimensional FEMs of realistic turbine airfoils using commercial finite element applications. The computationally predicted part life was calibrated and verified against test data for deformation and crack growth.

scholarly journals Numerical Simulation of Cracking in Asphalt Concrete Through Continuum and Discrete Damage Model

2021 ◽  
Vol 9 (11) ◽  
pp. 2018--2020
Author(s):  
Javed Iqbal
Keyword(s):  
Finite Element ◽  
Asphalt Concrete ◽  
Cohesive Zone ◽  
Cohesive Zone Model ◽  
Fracture Behaviour ◽  
Numerical Models ◽  
Damage Model ◽  
Element Model ◽  
Zone Model ◽  
Concrete Damage

Abstract: This study describes the development of Continuum and Discrete Damage Models in commercial finite element code Abaqus/Standard. The Concrete Damage Plasticity Model has been simulated, analysed, and compared the result with the experimental data. For verification, the Cohesive Zone Model has been simulated and analysed. Furthermore, the Extended Finite Element Model and concrete damage model are discussed and compared. The continuum damage model tends to simulate the complex fracture behaviour like crack initiation and propagation along with the invariance of the result, while the cohesive zone model can simulate and propagate the crack as well as the good agreement of the result. Further work in the proposed numerical models can better simulate the fracture behaviour of asphalt concrete in near future. Keywords: Model, Concrete, Cohesive Zone, Finite element, Abaqus.

scholarly journals Numerical analysis of the behavior of a three-layer honeycomb panel with interlayer defects under action of dynamic load

2021 ◽  
Vol 17 (4) ◽  
pp. 357-365
Author(s):  
Aleksandr L. Medvedskiy ◽  
Mikhail I. Martirosov ◽  
Anton V. Khomchenko ◽  
Darina V. Dedova
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Impact Load ◽  
Geometric Model ◽  
Three Dimensional ◽  
Element Model ◽  
Failure Criteria ◽  
Stress Fields ◽  
The Impact ◽  
Honeycomb Panel

The aim of the work is to study the effect of interlayer defects of the bundle type on the behavior of a rectangular flat three-layer panel with a honeycomb filler under the influence of a dynamic impact load. Methods. The problem was solved numerically using the finite element method in the Simcenter Femap and LS-DYNA (Livermore Software Technology Corp.) software complexes. For this purpose, a geometric model of a panel with a honeycomb placeholder was developed. Based on the geometric model, a finite element model of the panel was created using three-dimensional finite elements. In the software complexes, the finite element model was calculated under specified boundary conditions, then the stress fields and fracture indices in the panel were determined, taking into account and without taking into account damage. Results. The stress fields in the panel are numerically determined with and without defects. The fields of the failure indices of the panel layers under the impact load are investigated using various failure criteria (Puck, Hashin, LaRC03 (Langley Research Center)) of polymer composite materials. The analysis of the influence of a defect on the behavior of a honeycomb panel under the impact load is carried out.

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