scholarly journals Transient dynamic finite element simulation for prediction of surface integrity induced by waterjet peening

2019 ◽  
Vol 234 (1) ◽  
pp. 105-119
Author(s):  
Rihem Amri ◽  
Adnen Laamouri ◽  
Sondes Manchoul ◽  
Raouf Fathallah
Keyword(s):  
Finite Element ◽  
Surface Properties ◽  
Three Dimensional ◽  
Element Model ◽  
Transient Dynamic ◽  
Dynamic Finite Element ◽  
Impact Theory ◽  
Experimental Surface ◽  
Dimensional Simulation ◽  
The Impact

This paper aims to develop and validate the transient dynamic finite element three-dimensional simulation of a waterjet peening process to predict surface properties (residual stresses, plastic strains, surface roughness, and superficial damage). The finite-element model considers an impingement of multisets of droplets, which strike the treated surface by impact pressures over the corresponding contact regions at high velocities. The impact pressures and their durations are modelled by using the liquid impact theory combined with an impact velocity law depending on the main parameters of the process. The behavior law of the material is an elastoviscoplastic law coupled to the Johnson–Cook damage criterion. The effectiveness of this simulation is discussed in two cases: (i) a linear mono-set of droplets and (ii) multisets of droplets using the experimental results of a waterjet-peened Al7075-T6 aluminum alloy. The predictive results of surface properties obtained by simulation with multi-sets of droplets appear more realistic than those obtained by simulation with a single set of droplets and more close to the experimental surface properties.

A Three-Dimensional Dynamic Finite Element Model of the Prosthetic Knee Joint: Simulation of Joint Laxity and Kinematics

2005 ◽  
Vol 219 (6) ◽  
pp. 415-424 ◽  
Author(s):  
M Barink ◽  
A van Kampen ◽  
M de Waal Malefijt ◽  
N Verdonschot
Keyword(s):  
Finite Element ◽  
Knee Joint ◽  
Finite Element Model ◽  
Mathematical Formulation ◽  
Three Dimensional ◽  
Element Model ◽  
Joint Kinematics ◽  
Published Data ◽  
Dynamic Finite Element ◽  
Flexion Extension

For testing purposes of prostheses at a preclinical stage, it is very valuable to have a generic modelling tool, which can be used to optimize implant features and to avoid poor designs being launched on to the market. The modelling tool should be fast, efficient, and multipurpose in nature; a finite element model is well suited to the purpose. The question posed in this study was whether it was possible to develop a mathematically fast and stable dynamic finite element model of a knee joint after total knee arthroplasty that would predict data comparable with published data in terms of (a) laxities and ligament behaviour, and (b) joint kinematics. The soft tissue structures were modelled using a relatively simple, but very stable, composite model consisting of a band reinforced with fibres. Ligament recruitment and balancing was tested with laxity simulations. The tibial and patellar kinematics were simulated during flexion-extension. An implicit mathematical formulation was used. Joint kinematics, joint laxities, and ligament recruitment patterns were predicted realistically. The kinematics were very reproducible and stable during consecutive flexion-extension cycles. Hence, the model is suitable for the evaluation of prosthesis design, prosthesis alignment, ligament behaviour, and surgical parameters with respect to the biomechanical behaviour of the knee.

scholarly journals Three-Dimensional Simulation of Scalp Soft Tissue Expansion Using Finite Element Method

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Qiu Guan ◽  
Xiaochen Du ◽  
Yan Shao ◽  
Lili Lin ◽  
Shengyong Chen
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Soft Tissue ◽  
Three Dimensional ◽  
Tissue Expansion ◽  
Element Model ◽  
Size Number ◽  
Proposed Model ◽  
Dimensional Simulation ◽  
Element Method

Scalp soft tissue expansion is one of the key medical techniques to generate new skin tissue for correcting various abnormalities and defects of skin in plastic surgery. Therefore, it is very important to work out the appropriate approach to evaluate the increase of expanded scalp area and to predict the shape, size, number, and placement of the expander. A novel method using finite element model is proposed to solve large deformation of scalp expansion in this paper. And the procedure to implement the scalp tissue expansion with finite element method is also described in detail. The three-dimensional simulation results show that the proposed method is effective, and the analysis of simulation experiment shows that the volume and area of the expansion scalp can be accurately calculated and the quantity, location, and size of the expander can also be predicted successfully with the proposed model.

scholarly journals The Distributed Lambda (λ) Model (DLM): A 3-D, Finite-Element Muscle Model Based on Feldman's λ Model; Assessment of Orofacial Gestures

2013 ◽  
Vol 56 (6) ◽  
pp. 1909-1923 ◽  
Author(s):  
Mohammad Ali Nazari ◽  
Pascal Perrier ◽  
Yohan Payan
Keyword(s):  
Finite Element ◽  
Isometric Force ◽  
Three Dimensional ◽  
Element Model ◽  
Muscle Model ◽  
Type Model ◽  
Model Assessment ◽  
Model Based ◽  
Muscle Tissues ◽  
The Impact

Purpose The authors aimed to design a distributed lambda model (DLM), which is well adapted to implement three-dimensional (3-D), finite-element descriptions of muscles. Method A muscle element model was designed. Its stress–strain relationships included the active force–length characteristics of the λ model along the muscle fibers, together with the passive properties of muscle tissues in the 3-D space. The muscle element was first assessed using simple geometrical representations of muscles in the form of rectangular bars. It was then included in a 3-D face model, and its impact on lip protrusion was compared with the impact of a Hill-type muscle model. Results The force–length characteristic associated with the muscle elements matched well with the invariant characteristics of the λ model. The impact of the passive properties was assessed. Isometric force variation and isotonic displacements were modeled. The comparison with a Hill-type model revealed strong similarities in terms of global stress and strain. Conclusion The DLM accounted for the characteristics of the λ model. Biomechanically, no clear differences were found between the DLM and a Hill-type model. Accurate evaluations of the λ model, based on the comparison between data and simulations, are now possible with 3-D biomechanical descriptions of the speech articulators because of the DLM.

Optimization of the Engine Hood to Reduce the Head Injury during the Vehicle-Human Collision

2012 ◽  
Vol 192 ◽  
pp. 29-36
Author(s):  
Yu Xin Wang ◽  
Qing Chun Wang ◽  
Jian Rong Fu ◽  
Hong Hai Qiao
Keyword(s):  
Finite Element ◽  
Head Injury ◽  
Optimization Design ◽  
Three Dimensional ◽  
Element Model ◽  
Head Model ◽  
Modeling Software ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element ◽  
The Impact

Effect of hard point of the engine hood on the head injury during the vehicle-human collision was studied to improve the design of engine hood. Firstly, the current common model of the engine hood was established with three-dimensional finite element modeling software, and 20 areas were divided, also a standard head finite element model was imported, secondly, each area of the engine hood was clashed by the standard head model, then the impact on the head injure was analyzed and the hard point of the hood area was achieved, thirdly, the optimization of the inside and outside panel materials and the plate structure were carried out to reduce the head damage. The simulation results show that the engine hood after optimization gave less damage to the head, which means the research carried out here is of a good reference to the engine hood optimization design for human protection

Fracture Behavior of the Hot Rolled Strip’s Surface Scale Layer from Different Impacts Angles

2022 ◽  
Vol 905 ◽  
pp. 67-72
Author(s):  
Shang Wang ◽  
Rui Can Hao ◽  
Hua Gang Liu ◽  
Xiao Chen Wang ◽  
Quan Yang
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Element Model ◽  
Impact Angle ◽  
Rolled Strip ◽  
Shot Blasting ◽  
Cracking Behavior ◽  
Scale Layer ◽  
Hot Rolled ◽  
The Impact

In order to improve the energy efficiency of shot blasting impact descaling, a three-dimensional finite element impact descaling model was established. Based on the finite element model, the cracking behavior of the scale layer on hot rolled strip from different impacts angles was simulated. The results of finite element calculation and theoretical analysis show that: (1)Under the premise of constant velocity, the descaling area increases with the increase of impact angle, but the increasing rate tends to be moderate. (2)The depth of the impact tunnel and the residual compressive stress surface (-200 MPa) increase as the impact angle goes bigger. The ideal range of impact angle for shot blasting descaling should be 60°-75°.

Simulation and Test for the Lightning Damage of the Glass Fiber Composites

2014 ◽  
Vol 1003 ◽  
pp. 78-84
Author(s):  
Xiao Ning Chen ◽  
Jin Long Zhao ◽  
Yun Sheng Zhang ◽  
Bin Zhang
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Element Model ◽  
Damage Mechanism ◽  
Glass Fiber Composites ◽  
Dimensional Finite Element ◽  
Aircraft Composites ◽  
Three Dimensional Finite Element ◽  
The Impact ◽  
Composites Panel

Theoretical deducing, simulated lightning test and finite element simulation are used to research the mechanism and state of lightning damage of the aircraft composites sandwich panels. It provides the basis for the design of the aircraft lightning protection. The three-dimensional finite element model of the composites panel is constructed through the thermal electrical-mechanical multi-Physics coupling field. According to the structure and the role process, the lightning effect of the aircraft composites is analysed to study the damage mechanism and the possible state of the composites panel that is struck by lightning. The impact current generator is used to carry out the simulated lightning test to observe the lightning effect of the composites panel. By comparing the results of the test and the simulation, the effectiveness and the correctness of the simulation are verified.

Deicing Excitation Simulation and Structural Dynamic Analysis of the Electro-Impulse Deicing System

2011 ◽  
Vol 66-68 ◽  
pp. 390-395 ◽  
Author(s):  
Qing Ying Li ◽  
Tian Bai ◽  
Chun Ling Zhu
Keyword(s):  
Finite Element ◽  
Dynamic Analysis ◽  
Three Dimensional ◽  
Element Model ◽  
Field Analysis ◽  
Post Processing ◽  
Analysis Model ◽  
Structural Dynamic ◽  
Dynamic Finite Element ◽  
Ice Failure

A two-dimensional electromagnetic eddy current field analysis model of the experimental electro-impulse deicing system (EIDI) is developed. Additionally, a numerical post-processing method is proposed to calculate the deicing excitation exerting on the testing skin. Moreover, a three-dimensional dynamic analysis finite element model of the testing skin loaded the excitation is built for evaluating the response accelerations. Then, the calculated accelerations are compared with the experimental measured data to validate the correctness of the proposed methods. It is obtained that the results agree well, which indicates that it is feasible to use the method of post-processing pressure distribution for solving the deicing excitation and the method of structural dynamic finite element analyzing the testing skin for simulating dynamic response. The presented methods pave a way for ice failure analysis of the EIDI system.

scholarly journals Stope Stability Assessment and Effect of Horizontal to Vertical Stress Ratio on the Yielding and Relaxation Zones Around Underground Open Stopes Using Empirical and Finite Element Methods

2017 ◽  
Vol 62 (3) ◽  
pp. 653-669 ◽  
Author(s):  
Mohammadali Sepehri ◽  
Derek Apel ◽  
Wei Liu
Keyword(s):  
Finite Element ◽  
Numerical Methods ◽  
Stress Ratio ◽  
Three Dimensional ◽  
Element Model ◽  
Underground Mine ◽  
Graph Method ◽  
The Stability ◽  
Stability Graph ◽  
The Impact

AbstractPredicting the stability of open stopes can be a challenging task for underground mine engineers. For decades, the stability graph method has been used as the first step of open stope design around the world. However, there are some shortcomings with this method. For instance, the stability graph method does not account for the relaxation zones around the stopes. Another limitation of the stability graph is that this method cannot to be used to evaluate the stability of the stopes with high walls made of backfill materials. However, there are several analytical and numerical methods that can be used to overcome these limitations. In this study, both empirical and numerical methods have been used to assess the stability of an open stope located between mine levels N9225 and N9250 at Diavik diamond underground mine. It was shown that the numerical methods can be used as complementary methods along with other analytical and empirical methods to assess the stability of open stopes. A three dimensional elastoplastic finite element model was constructed using Abaqus software. In this paper a sensitivity analysis was performed to investigate the impact of the stress ratio “k” on the extent of the yielding and relaxation zones around the hangingwall and footwall of the understudy stope.

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