scholarly journals A Finite Element Model to Investigate the Impact of Torch Angle on an Autogenous TIG Welding Process

2017 ◽  
Vol 05 (04) ◽  
pp. 743-753
Author(s):  
Richard Turner
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Welding Process ◽  
Element Model ◽  
Tig Welding ◽  
Torch Angle ◽  
The Impact

Behavior of Structures Using Simple Plastic Hinge Theory

1994 ◽  
Author(s):  
Ramakrishnan Maruthayappan ◽  
Hamid M. Lankarani
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Cantilever Beam ◽  
Reliable Method ◽  
Plastic Hinge ◽  
Element Model ◽  
Finite Element Models ◽  
Computational Program ◽  
Hinge Model ◽  
The Impact

Abstract The behavior of structures under the impact or crash situations demands an efficient modeling of the system for its behavior to be predicted close to practical situations. The various formulations that are possible to model such systems are spring mass models, finite element models and plastic hinge models. Of these three techniques, the plastic hinge theory offers a more accurate model compared to the spring mass formulation and is much simpler than the finite element models. Therefore, it is desired to model the structure using plastic hinges and to use a computational program to predict the behavior of structures. In this paper, the behavior of some simple structures, ranging from an elementary cantilever beam to a torque box are predicted. It is also shown that the plastic hinge theory is a reliable method by comparing the results obtained from a plastic hinge model of an aviation seat structure with that obtained from a finite element model.

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.

A Thermal Model for Ultrasonic Welding of Thermoplastics

2007 ◽  
Author(s):  
S.-F. Ling ◽  
X. Li ◽  
Z. Sun
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Equivalent Circuit Model ◽  
Welding Process ◽  
Element Model ◽  
Ultrasonic Welding ◽  
Joint Interface ◽  
Mems Devices ◽  
Transient Heating ◽  
Temperature Distributions

Ultrasonic welding is one of the most popular techniques for joining thermoplastics and plays an important role in MEMS applications such as fabrication and packaging of MEMS devices. In this paper, an attempt was made to further understand the heating mechanism during ultrasonic welding. Firstly, the equation governing heat generation was derived assuming adiabatic heating. A thermal equivalent circuit model was also developed to describe the heat transfer process from the joint interface into the surroundings, and the governing equation of temperature distribution in the welding sample was deduced. Finite element method was then engaged to solve these equations to reveal the transient heating behaviour. Lastly, temperatures of the joint interface and the point adjacent to the joint were measured. The temperatures of the point adjacent to the joint calculated from finite element model are matched well with the experimental results. Based on the correlation, the temperature distributions of welding samples can be derived from the finite element model. Since the new developed model can be used to obtain the dynamic temperature distributions of welding samples during ultrasonic welding, the model provides an effective way for detailed understanding of the thermal behaviours and monitoring of the ultrasonic welding process.

Biomechanical Comparison of Real World Concussive Impacts in Children, Adolescents, and Adults

2020 ◽  
Vol 142 (7) ◽  
Author(s):  
Lauren Dawson ◽  
David Koncan ◽  
Andrew Post ◽  
Roger Zemek ◽  
Michael D. Gilchrist ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Brain Tissue ◽  
Dynamic Models ◽  
Element Model ◽  
Tissue Response ◽  
Model Simulations ◽  
Child Group ◽  
Adolescents And Adults ◽  
The Impact

Abstract Accidental falls occur to people of all ages, with some resulting in concussive injury. At present, it is unknown whether children and adolescents are at a comparable risk of sustaining a concussion compared to adults. This study reconstructed the impact kinematics of concussive falls for children, adolescents, and adults and simulated the associated brain tissue deformations. Patients included in this study were diagnosed with a concussion as defined by the Zurich Consensus guidelines. Eleven child, 10 adolescent, and 11 adult falls were simulated using mathematical dynamic models(MADYMO), with three ellipsoid pedestrian models sized to each age group. Laboratory impact reconstruction was conducted using Hybrid III head forms, with finite element model simulations of the brain tissue response using recorded impact kinematics from the reconstructions. The results of the child group showed lower responses than the adolescent group for impact variables of impact velocity, peak linear acceleration, and peak rotational acceleration but no statistical differences existed for any other groups. Finite element model simulations showed the child group to have lower strain values than both the adolescent and adult groups. There were no statistical differences between the adolescent and adult groups for any variables examined in this study. With the cases included in this study, young children sustained concussive injuries at lower modeled brain strains than adolescents and adults, supporting the theory that children may be more susceptible to concussive impacts than adolescents or adults.

scholarly journals Characterization of Adhesives Bonding in Aircraft Structures

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4816
Author(s):  
Maria Grazia Romano ◽  
Michele Guida ◽  
Francesco Marulo ◽  
Michela Giugliano Auricchio ◽  
Salvatore Russo
Keyword(s):  
Finite Element ◽  
Composite Material ◽  
Finite Element Model ◽  
Impact Energy ◽  
Element Model ◽  
Cohesive Zone Modeling ◽  
Main Task ◽  
Opening Displacement ◽  
Lap Shear ◽  
The Impact

Structural adhesives play an important role in aerospace manufacturing, since they provide fewer points of stress concentration compared to faster joints. The importance of adhesives in aerospace is increasing significantly because composites are being adopted to reduce weight and manufacturing costs. Furthermore, adhesive joints are also studied to determine the crashworthiness of airframe structure, where the main task for the adhesive is not to dissipate the impact energy, but to keep joint integrity so that the impact energy can be consumed by plastic work. Starting from an extensive campaign of experimental tests, a finite element model and a methodology are implemented to develop an accurate adhesive model in a single lap shear configuration. A single lap joint finite element model is built by MSC Apex, defining two specimens of composite material connected to each other by means of an adhesive; by the Digimat multi-scale modeling solution, the composite material is treated; and finally, by MSC’s Marc, the adhesive material is characterized as a cohesive applying the Cohesive Zone Modeling theory. The objective was to determine an appropriate methodology to predict interlaminar crack growth in composite laminates, defining the mixed mode traction separation law variability in function of the cohesive energy (Gc), the ratio between the shear strength τ and the tensile strength σ (β1), and the critical opening displacement υc.

Structural Optimization Scheme for Horizontal Filtering Tank

2014 ◽  
Vol 577 ◽  
pp. 310-313
Author(s):  
Ping Yang ◽  
Zhou De Qu ◽  
Min Li
Keyword(s):  
Finite Element ◽  
Optimal Design ◽  
Finite Element Model ◽  
Element Model ◽  
Structural Instability ◽  
Optimization Scheme ◽  
Design Scheme ◽  
Operation Process ◽  
The Impact ◽  
The Finite Element Model

Based on the impact of some horizontal filtering tank’s instability in operation process on production, the present paper discusses the optimal design scheme for horizontal filtering tank structure with the help of finite element. Theoretical guidance will be given to enterprise from the perspective of finite element for the purpose of improving the horizontal filtering tank through constructing the finite element model for horizontal filtering tank with Creo parametric software, conducting simulation with workbench software[1] and finally arriving at the reasonable design scheme after analysis, thus avoiding the structural instability caused by the over-constraint of structural leg support beam and filter plate under-constraint.

The Analysis on Suspension of Fire Robot Based on FEA

2014 ◽  
Vol 716-717 ◽  
pp. 1536-1539
Author(s):  
Yan Xu ◽  
Shu Fang ◽  
Jian Qiao Fu
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Stress Condition ◽  
Impact Load ◽  
Element Model ◽  
Force Condition ◽  
Environmental Adaptability ◽  
The Impact ◽  
Suspension Structure

The suspension of fire robot, one of necessary components, directly impacts the environmental adaptability, and the strength of suspension has great importance to the life of robot. In the paper, the structure and the stress condition of the suspension was analyzed. The force condition of suspension is simplified as a 2-D diagram, the load acting on the elbow were simplified in two direction, A finite element model, which simulated the impact load and optimized the design of suspension, was established, and the result of the simulation shows the suspension structure is reasonable and the strength of the component is enough.

Modeling of a Rear-End Crash Pulse Generator

2012 ◽  
Vol 630 ◽  
pp. 360-365
Author(s):  
Hai Bin Chen ◽  
Ling Zhang ◽  
Li Ying Zhang ◽  
Xue Mei Cheng ◽  
Zheng Guo Wang
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Pulse Generator ◽  
Element Model ◽  
Outer Diameter ◽  
Time Curve ◽  
International Regulation ◽  
Safety Research ◽  
The Impact ◽  
Deceleration Time

The rear-end crash pulse generator has been considered to be a key device for performing car impact safety research under laboratory conditions. According to the international regulation, ECE R44, the polyurethane (PU) tube was recommended to produce a standard rear-end pulse. However, little literatures on the impact dynamics of PU tube were known. In this study, a was established under ANSYS/LS-DYNA. With this finite element model, the following conditions to generate the standard rear-end impact pulses were determined: the initial impact velocity of sled was 30km/h, the resultant mass of sled was 680kg, number of PU-tubes was three, and outer diameter of olive knob was 46mm. Compared with the standard deceleration-time curve of actual rear-end crash, this finite element model of rear-end crash pulse generator was preliminarily validated.

scholarly journals Visualization of the Process of Processing Welds by a Deformation Wave

2020 ◽  
pp. short39-1-short39-7
Author(s):  
Andrey Kirichek ◽  
Sergey Barinov ◽  
Alexandr Yashin
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Visual Information ◽  
Calculated Data ◽  
Welding Process ◽  
Element Model ◽  
Temperature Fields ◽  
Subsequent Stage ◽  
Deformation Wave ◽  
Complex Process

The aim of the paper is to obtain a unified finite element model of a complex process, which makes it possible to obtain visual information related to the influence of the welding process parameters on the results of the process of wave strain hardening of the weld material. Modeling of sequentially executed technological processes of different physical nature - welding and hardening, makes it possible to obtain more general and objective visual information about the process as a whole. Modeling in the Ansys software package is performed in stages, with the output of an earlier stage of modeling acting as the input data of the subsequent stage. At the first stage, the problem of visualizing the process of forming a weld is solved with the possibility of calculating temperature fields, stress and strain fields during heating and cooling of the welded workpiece. At the second stage, the calculated data is imported into the finite element model of processing welds with a deformation wave. A finite element model makes it possible to build microhardness maps for selected (dangerous) sections and visually monitor the change in stresses and strains in welded workpieces, depending on the technological modes of hardening by a deformation wave. The obtained visual information allows for a qualitative and quantitative assessment of the result of a complex process, which contributes to an increase in the bearing capacity and performance of the product as a whole.

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