scholarly journals Numerical Simulation on Carbonation Depth of Concrete Structures considering Time- and Temperature-Dependent Carbonation Process

2018 ◽  
Vol 2018 ◽  
pp. 1-16 ◽  
Author(s):  
Jianxin Peng ◽  
Huang Tang ◽  
Jianren Zhang ◽  
Steve C. S. Cai
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Concrete Structures ◽  
Element Model ◽  
Temperature Dependent ◽  
Mass Transfer Equation ◽  
Carbonation Depth ◽  
Concrete Carbonation ◽  
Carbonation Process ◽  
Element Method

In order to further understand the carbonation process of concrete structures, the time- and temperature-dependent diffusion process of CO2 in concrete is simulated based on the law of the CO2 mass conservation, and a two-dimensional mass transfer equation is established for the CO2 diffusion in concrete. The concrete block is discretized into triangular elements, and the CO2 concentrations at different positions are calculated based on finite element method. A computational algorithm is programed through the Matlab platform. The time- and temperature-dependent property and difference of the CO2 concentration at different positions of the structure are considered in the proposed model. Then, an accelerated carbonation experiment is carried out using concrete blocks with different mix proportions to investigate the influence of the water-cement ratio and temperature on the concrete carbonation. The experimental results effectively verify the correctness of the finite element model, and the proposed finite element method reasonably simulates the concrete carbonation through calculating the carbonation in practical engineering compared with other methods in references. An experimental-numerical correlation has been performed. The ratio of carbonation depth at the corner of the concrete members to the other positions is about 1.35. The carbonation depth is increased about 1.9 times when the temperature changes from 20°C to 40°C.

scholarly journals Finite Element Method modeling of Additive Manufactured Compressor Wheel

2021 ◽  
Author(s):  
Márton Tamás Birosz ◽  
Mátyás Andó ◽  
Sudhanraj Jeganmohan
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Finite Element Method Simulation ◽  
Element Model ◽  
Tensile Tests ◽  
Raw Material ◽  
Isotropic Hardening ◽  
Compressor Wheel ◽  
Material Extrusion ◽  
Element Method

AbstractDesigning components is a complex task, which depends on the component function, the raw material, and the production technology. In the case of rotating parts with higher RPM, the creep and orientation are essential material properties. The PLA components made with the material extrusion process are more resistant than VeroWhite (material jetting) and behave similarly to weakly cross-linked elastomers. Also, based on the tensile tests, Young’s modulus shows minimal anisotropy. Multilinear isotropic hardening and modified time hardening models are used to create the finite element model. Based on the measurements, the finite element method simulation was identified. The deformation in the compressor wheel during rotation became definable. It was concluded that the strain of the compressor wheel manufactured with material extrusion technology is not significant.

An inhomogeneous cell-based smoothed finite element method for the nonlinear transient response of functionally graded magneto-electro-elastic structures with damping factors

2018 ◽  
Vol 30 (3) ◽  
pp. 416-437 ◽  
Author(s):  
Liming Zhou ◽  
Ming Li ◽  
Bingkun Chen ◽  
Feng Li ◽  
Xiaolin Li
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Element Model ◽  
Micro Electro Mechanical System ◽  
Functionally Graded ◽  
Elastic Structures ◽  
Mapping Procedure ◽  
Gaussian Integration ◽  
Smoothed Finite Element Method ◽  
Element Method

In this article, an inhomogeneous cell-based smoothed finite element method (ICS-FEM) was proposed to overcome the over-stiffness of finite element method in calculating transient responses of functionally graded magneto-electro-elastic structures. The ICS-FEM equations were derived by introducing gradient smoothing technique into the standard finite element model; a close-to-exact system stiffness was also obtained. In addition, ICS-FEM could be carried out with user-defined sub-routines in the business software now available conveniently. In ICS-FEM, the parameters at Gaussian integration point were adopted directly in the creation of shape functions; the computation process is simplified, for the mapping procedure in standard finite element method is not required; this also gives permission to utilize poor quality elements and few mesh distortions during large deformation. Combining with the improved Newmark scheme, several numerical examples were used to prove the accuracy, convergence, and efficiency of ICS-FEM. Results showed that ICS-FEM could provide solutions with higher accuracy and reliability than finite element method in analyzing models with Rayleigh damping. Such method is also applied to complex structures such as typical micro-electro-mechanical system–based functionally graded magneto-electro-elastic energy harvester. Hence, ICS-FEM can be a powerful tool for transient problems of functionally graded magneto-electro-elastic models with damping which is of great value in designing intelligence structures.

scholarly journals Analysis of Vertical Stiffness of Air Spring Based on Finite Element Method

2018 ◽  
Vol 153 ◽  
pp. 06006
Author(s):  
Jiatong Ye ◽  
Hua Huang ◽  
Chenchen He ◽  
Guangyuan Liu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Finite Element Simulation ◽  
Element Model ◽  
Simulation Method ◽  
Bench Test ◽  
Air Spring ◽  
Vertical Stiffness ◽  
Element Simulation ◽  
Element Method

In this paper, a finite element model of membrane air spring in the vehicle is established, and its vertical stiffness characteristics under a certain inflation pressure are analysed. The result of finite element simulation method is compared with the result of the air spring bench test. The accuracy and reliability of the finite element simulation method in nonlinear analysis of air spring system are verified. In addition, according to the finite element method, the influence of the installation of the air spring limit sleeve on its stiffness is verified.

scholarly journals Prediction of Characteristic Length and Fracture Toughness in Ductile-Brittle Transition

2008 ◽  
Author(s):  
Z. X. Wang ◽  
H. M. Li ◽  
Y. J. Chao ◽  
P. S. Lam
Keyword(s):  
Finite Element Method ◽  
Fracture Toughness ◽  
Finite Element ◽  
Characteristic Length ◽  
Crack Tip ◽  
Critical Distance ◽  
Transition Regime ◽  
Temperature Dependent ◽  
Brittle Transition ◽  
Element Method

Finite element method was used to analyze the three-point bend experimental data of A533B-1 pressure vessel steel obtained by Sherry, Lidbury, and Beardsmore [1] from −160 to −45 °C within the ductile-brittle transition regime. As many researchers have shown, the failure stress (σf) of the material could be approximated as a constant. The characteristic length, or the critical distance (rc) from the crack tip, at which σf is reached, is shown to be temperature dependent based on the crack tip stress field calculated by the finite element method. With the J-A2 two-parameter constraint theory in fracture mechanics, the fracture toughness (JC or KJC) can be expressed as a function of the constraint level (A2) and the critical distance rc. This relationship is used to predict the fracture toughness of A533B-1 in the ductile-brittle transition regime with a constant σf and a set of temperature-dependent rc. It can be shown that the prediction agrees well with the test data for wide range of constraint levels from shallow cracks (a/W = 0.075) to deep cracks (a/W = 0.5), where a is the crack length and W is the specimen width.

scholarly journals COMPARISON OF SAW BLADE NATURAL FREQUENCIES AND CRITICAL SPEEDS USING CSAW AND FINITE ELEMENT ANALYSIS

2011 ◽  
Author(s):  
J. Poirier ◽  
P. Radziszewski
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Natural Frequencies ◽  
Element Model ◽  
The Finite Element Method ◽  
Element Analysis ◽  
Saw Blade ◽  
Circular Saws ◽  
The Finite Element Model ◽  
Element Method

The natural frequencies of circular saws limit the operating speeds of the saws. Current industry methods of increasing natural frequency include pretensioning, where plastic deformation is induced into the saw. To better model the saw, the finite element model is compared to current software for steel saws; C-SAW, a software program that calculates frequencies for stiffened circular saws. Using C-SAW and the finite element method the results are compared and the finite element method is validated for steel saws.

Strength Analysis of the Seat Anchorages for Large Passenger Vehicles Using Finite Element Method

2013 ◽  
Vol 658 ◽  
pp. 340-344
Author(s):  
Somsak Siwadamrongpong ◽  
Supakit Rooppakhun ◽  
Natchaya Murachai ◽  
Pakorn Burakorn
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Element Model ◽  
Strength Analysis ◽  
Passenger Vehicle ◽  
Simulation Techniques ◽  
Vehicle Accident ◽  
Design For Safety ◽  
Vehicle Seat ◽  
Element Method

Since the vehicle accident is one of the major causes of dead and injury in Thailand, especially the large passenger vehicle. The seat anchorage was often damaged and lead to high number and critical of patient. To improve the safety of large passenger vehicle, seat anchorage should be investigated. The aim of this research was to analyze strength of seat anchorages for the bus according to European standard ECE Regulation 80 using finite element method and DOE(Design of Experimental) approach. In this study, the boundary conditions on finite element model of seat structure were defined according to the regulation. It is expected that the simulation techniques could be advantaged for seat anchorage analysis. This result will be used for further improvement of the bus seat anchorage design for safety and cost reduction in design processes.

Pipeline On-Bottom Stability Analysis Based on FEM Model

2011 ◽  
Author(s):  
Yong Bai ◽  
Zhimeng Yu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Design Procedure ◽  
Element Model ◽  
The Finite Element Method ◽  
Fem Model ◽  
Engineering Software ◽  
Calculation Results ◽  
Pipeline Design ◽  
Element Method

Pipeline on-bottom stability is one of the sophisticated problems in subsea pipeline design procedure. Due to the uncertainty of the pipe-soil interaction and environment loads, including wave, current, or earthquake, etc., it is classified as the typical nonlinear problem. The Finite Element Method is introduced into pipeline engineering several years ago. More and more special engineering software such as AGA, PONDUS are available in market. However, when doing a project, some abnormal data was found when compared the DnV calculation results and AGA. In order to know the behavior of pipeline on seabed under wave and current load, finite element method – ABAQUS is introduced to do this analysis. The ABAQUS/explicit is used to simulate 600s pipeline dynamic response. The pipeline is supposed to be exposed on seabed and the selected seabed model is large enough to avoid the edge effect. ABAQUS calculation results are compared with the requirements in DnV rules to verify the validity of finite element model.

Modeling and Simulation of High Speed Intermittent Cutting Based on the Finite Element Method

2013 ◽  
Vol 683 ◽  
pp. 556-559
Author(s):  
Bin Bin Jiao ◽  
Fu Sheng Yu ◽  
Yun Jiang Li ◽  
Rong Lu Zhang ◽  
Gui Lin Du ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Stress Field ◽  
Cutting Force ◽  
High Speed ◽  
Element Model ◽  
Periodic Variation ◽  
Element Analysis ◽  
Intermittent Cutting ◽  
Element Method

In order to study the distribution of the stress field in the high-speed intermittent cutting process, finite element model of high-speed intermittent cutting is established. Exponential material model of the constitutive equation and adaptive grid technology are applied in the finite element analysis software AdvantEdge. The material processing is simulated under certain cutting conditions with FEM ( Finite Element Method ) and the distribution of cutting force, stress field, and temperature field are received. A periodic variation to the cutting force and temperature is showed in the simulation of high-speed intermittent cutting. Highest value of the milling temperature appears in front contacting area of the knife -the chip.and maximum stress occurs at the tip of tool or the vicinity of the main cutting edge. The analysis of stress and strain fields in-depth is of great significance to improve tool design and durability of tool.

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