scholarly journals Guidelines for Geotechnical Finite-Element Modeling

2021 ◽  
Vol 15 (1) ◽  
pp. 424-440
Author(s):  
Ahmed Elgamal
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Finite Element Modeling ◽  
Knowledge Base ◽  
Test Data ◽  
Experimental Test ◽  
Constitutive Models ◽  
Element Model ◽  
Soil Behavior ◽  
Finite Element Software

This paper emphasizes on the required guidelines for establishing a geotechnical finite-element model. The steps that must be taken to construct such a model are explained in a flowchart, and the methodology described therein is illustrated by building a model using commercially available finite-element software. Well-documented experimental test data are used to validate the model results. The effects of the geometry plotting, meshing techniques, and boundary locations are assessed by comparing the model results with the experimental results. To date, various geotechnical constitutive models have been proposed to describe various aspects of actual soil behavior in detail, and the advantages and limitations of five such models are discussed. The model results are subjected to an assessment check. The geotechnical modeler can be decided based on the knowledge base that constitutive models will use as the case.

Updating Finite Element Model of Combined Structures on the Basis of Dynamic Test Results

1996 ◽  
Author(s):  
Chen Xin ◽  
Qin Ye ◽  
Yuan Xiguang ◽  
Zhang Ping ◽  
Sun Jian
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Test Data ◽  
Dynamic Test ◽  
Element Model ◽  
Physical Parameters ◽  
Structural Joint ◽  
Combined Structure ◽  
Joint Parameters ◽  
Two Stages

Abstract According to the real situation, a new method of updating the finite element model (FEM) of a combined structure step by step is proposed in this paper. It is assumed that there are two types of error when establishing the FEMs. One of them results from the simplifications, in fact, it is severe for complicated structures, which usually assume many simplifications; the other is from the process of identifying structural joint parameters. For this reason, it is recommended that the FEM should be established in two stages. At the first stage, the local physical parameters relating with the simplifications are corrected by using the dynamic test data of the corresponding substructures. Then, the structural joint parameters that link the substructures are corrected by the dynamic test data of the combined structure as a whole. The updating formula is presented and proved, and its algorithm is also described. And the experimental results show that the efficiency and accuracy of the proposed method are quite satisfactory.

scholarly journals Analysis for Wrinkling Behavior of Girth-Welded Line Pipe

1996 ◽  
Author(s):  
Luiz T. Souza ◽  
David W. Murray
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Finite Element Model ◽  
Internal Pressure ◽  
Experimental Test ◽  
Element Model ◽  
Element Analysis ◽  
Line Pipe ◽  
New Era ◽  
Analytical Tools

The paper presents results for finite element analysis of full-sized girth-welded specimens of line pipe and compares these results with the behavior exhibited by test specimens subjected to constant axial force, internal pressure and monotonically increasing curvatures. Recommendations for the ‘best’ type of analytical finite element model are given. Comparisons between the behavior predicted analytically and the observed behavior of the experimental test specimens are made. The mechanism of wrinkling is explained and the evolution of the deformed configurations for different wrinkling modes is examined. It is concluded that the analytical tools now available are sufficiently reliable to predict the behavior of pipe in a manner that was not previously possible and that this should create a new era for the design and assessment of pipelines if the technology is properly exploited by industry.

scholarly journals Biaxial estimation of biomechanical constitutive parameters of passive porcine sclera soft tissue

2021 ◽  
Author(s):  
Zwelihle Ndlovu ◽  
Dawood Desai ◽  
Thanyani Pandelani ◽  
Harry Ngwangwa ◽  
Fulufhelo Nemavhola
Keyword(s):  
Finite Element ◽  
Soft Tissue ◽  
Finite Element Model ◽  
Test Data ◽  
Element Model ◽  
Finite Element Models ◽  
Anisotropic Model ◽  
Material Models ◽  
Material Parameters ◽  
Constitutive Parameters

This study assesses the modelling capabilities of four constitutive hyperplastic material models to fit the experimental data of the porcine sclera soft tissue. It further estimates the material parameters and discusses their applicability to a finite element model by examining the statistical dispersion measured through the standard deviation. Fifteen sclera tissues were harvested from porcine’ slaughtered at an abattoir and were subjected to equi-biaxial testing. The results show that all the four material models yielded very good correlations at correlations above 96 %. The polynomial (anisotropic) model gave the best correlation of 98 %. However, the estimated material parameters varied widely from one test to another such that there would be needed to normalise the test data to avoid long optimisation processes after applying the average material parameters to finite element models. However, for application of the estimated material parameters to finite element models, there would be needed to consider normalising the test data to reduce the search region for the optimisation algorithms. Although the polynomial (anisotropic) model yielded the best correlation, it was found that the Choi-Vito had the least variation in the estimated material parameters thereby making it an easier option for application of its material parameters to a finite element model and also requiring minimum effort in the optimisation procedure. For the porcine sclera tissue, it was found that the anisotropy more influenced by the fiber-related properties than the background material matrix related properties.

Experimentally validated predictive finite element modeling of the V0-V100 probabilistic penetration response of a Kevlar fabric against a spherical projectile

2018 ◽  
Vol 9 (4) ◽  
pp. 504-524 ◽  
Author(s):  
Gaurav Nilakantan
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Finite Element Modeling ◽  
Element Model ◽  
Ballistic Impact ◽  
Impact Testing ◽  
Woven Fabric ◽  
Projectile Impact ◽  
Element Modeling ◽  
The Impact

This work presents the first fully validated and predictive finite element modeling framework to generate the probabilistic penetration response of an aramid woven fabric subjected to ballistic impact. This response is defined by a V0-V100 curve that describes the probability of complete fabric penetration as a function of projectile impact velocity. The exemplar case considered in this article comprises a single-layer, fully clamped, plain-weave Kevlar fabric impacted at the center by a 0.22 cal spherical steel projectile. The fabric finite element model comprises individually modeled three-dimensional warp and fill yarns and is validated against the experimental material microstructure. Sources of statistical variability including yarn strength and modulus, inter-yarn friction, and precise projectile impact location are mapped into the finite element model. A series of impact simulations at varying projectile impact velocities is executed using LS-DYNA on the fabric models, each comprising unique mappings. The impact velocities and outcomes (penetration, non-penetration) are used to generate the numerical V0-V100 curve which is then validated against the experimental V0-V100 curve obtained from ballistic impact testing and shown to be in excellent agreement. The experimental data and its statistical analysis used for model input and validation, namely, the Kevlar yarn tensile strengths and moduli, inter-yarn friction, and fabric ballistic impact testing, are also reported.

Mechanical Analysis of Porous Concrete Base in Asphalt Pavement

2012 ◽  
Vol 443-444 ◽  
pp. 751-756
Author(s):  
Li Jun Suo ◽  
Xia Guang Hu
Keyword(s):  
Finite Element ◽  
Thermal Stress ◽  
Finite Element Model ◽  
Design Method ◽  
Asphalt Pavement ◽  
Element Model ◽  
Three Dimension ◽  
Porous Concrete ◽  
Finite Element Software ◽  
Concrete Base

In China, it is fact that porous concrete base has been used in the construction of asphalt pavement in recent years because porous concrete base has good performance. However, Reasonable design method has not been put forward so far. Therefore, it is necessary to analyze load stress and thermal stress of asphalt pavement which includes porous concrete base in order to put forward theoretical basis for pavement design method. In the paper, three–dimension finite element model of asphalt pavement, which includes porous concrete base and asphalt surface, is created for the purpose of studying load stress and thermal stress of porous concrete base in asphalt pavement. Based on numerical method of three–dimension finite element model, finite element software, such as ANSYS, is employed to study load stress and thermal stress of porous concrete base in asphalt pavement. After that, the effect of different factors on stress is studied, and the factors include thickness of surface, thickness of base and ratio of base’s modulus to foundation’s modulus. Finally, calculation results for stress are compared with each other, and it shows that load stress of porous concrete base decreases with increase of base’s thickness, while thermal stress of porous concrete base increases with increase of base’s thickness. Load stress and thermal stress of porous concrete base decrease with increase of surface’s thickness. Load stress and thermal stress of porous concrete base increase with increase of ratio of base’s modulus to foundation’s modulus.

Design and Simulation of the New Bionic Soil Extruding Head

2012 ◽  
Vol 479-481 ◽  
pp. 457-461
Author(s):  
Dong Hui Chen ◽  
Xin Lu ◽  
Xing Wang Chai ◽  
Bao Gang Wang ◽  
Hong Xia Guo ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Simulation Model ◽  
Element Model ◽  
Maximum Force ◽  
Soil Parameters ◽  
Drilling Depth ◽  
Finite Element Software ◽  
Changing Trends ◽  
The Finite Element Model

In this paper，soil parameters and the collected data were tested and processed, and the changing trends of force with drilling depth were obtained and the maximum force applying to the working components was picked up. Compared with the smooth working component, the force applying to the unsmooth working components is smaller. Some parameters needed in Drucker-Prager soil model were measured and modified according to the basic tests. The simulation model was built in the finite element software -ANSYS. The simulation result is consistent with the actual testing result, which confirms the finite element model is correct .

Study on Finite Element Model of Bridge Multi-Pile Foundation

2010 ◽  
Vol 456 ◽  
pp. 103-114
Author(s):  
Shi Ling Xing ◽  
Jian Shu Ye ◽  
Hang Sun
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Pile Foundation ◽  
Bending Moment ◽  
Highway Bridges ◽  
Element Model ◽  
Boundary Constraints ◽  
Finite Element Software ◽  
Friction Pile ◽  
The Finite Element Model

In order to use finite element software to complete the design or calculation of bridge multi-pile foundation, this paper discusses the finite element model (FEM) of a bridge multi-pile based on the theory and provisions in Code for Design of Ground Base and Foundation of Highway Bridges and Culverts (CDGBFHBC 2007) of china. For the FEM of a bridge-multi pile foundation, cap is regarded as a rigid body, piles are taken as beams, and boundary constraints are a series of horizontal springs and vertical springs. First, the formula of stiffness for horizontal springs and bottom vertical spring is derived according to elastic ground base theory and winkler hypotheses. Secondly, for the friction pile, the stiffness of vertical springs on piles side is derived basis of the principle of friction generated and simplified distribution of pile shaft resistance. Then, the FEM of multi-pile needs pay attention to three issues: the simulation of connections between piles and cap, elastic modulus needs discount, and the weight for pile underneath the ground line (or local scour line) needs calculate by half. Taking pile section bending moment often control the design and calculation of pile into account, this paper gives a simplified FEM of pile. Finally, an example is used to introduce the application of the FEM of bridge multi-pile foundation.

Static and Dynamic Finite Element Model Updating of a Rigid Frame-Continuous Girders Bridge Based on Response Surface Method

2013 ◽  
Vol 639-640 ◽  
pp. 992-997 ◽  
Author(s):  
Jian Ping Han ◽  
Yong Peng Luo
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Response Surface ◽  
Test Data ◽  
Dynamic Test ◽  
Element Model ◽  
Surface Method ◽  
Rigid Frame ◽  
The Finite Element Model

Using the static and dynamic test data simultaneously to update the finite element model can increase the available information for updating. It can overcome the disadvantages of updating based on static or dynamic test data only. In this paper, the response surface method is adopted to update the finite element model of the structure based on the static and dynamic test. Using the reasonable experiment design and regression techniques, a response surface model is formulated to approximate the relationships between the parameters and response values instead of the initial finite element model for further updating. First, a numerical example of a reinforced concrete simply supported beam is used to demonstrate the feasibility of this approach. Then, this approach is applied to update the finite element model of a prestressed reinforced concrete rigid frame-continuous girders bridge based on in-situ static and dynamic test data. Results show that this approach works well and achieve reasonable physical explanations for the updated parameters. The results from the updated model are in good agreement with the results from the in-situ measurement. The updated finite element model can accurately represent mechanical properties of the bridge and it can serve as a benchmark model for further damage detection and condition assessment of the bridge.

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