scholarly journals Development of a Finite Element Model for Predicting the Impact Energy Absorbing Performance of a Composite Structure

2014 ◽  
Author(s):  
Matthew Lowell Roberts
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Impact Energy ◽  
Composite Structure ◽  
Element Model ◽  
Energy Absorbing ◽  
The Impact

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.

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.

Design and characterization of a hybrid soft gripper with active palm pose control

2020 ◽  
Vol 39 (14) ◽  
pp. 1668-1685 ◽  
Author(s):  
Vignesh Subramaniam ◽  
Snehal Jain ◽  
Jai Agarwal ◽  
Pablo Valdivia y Alvarado
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Composite Structure ◽  
Element Model ◽  
Open Loop ◽  
Aspect Ratios ◽  
Maximum Payload ◽  
Wide Range ◽  
Pose Control

The design and characterization of a soft gripper with an active palm to control grasp postures is presented herein. The gripper structure is a hybrid of soft and stiff components to facilitate integration with traditional arm manipulators. Three fingers and a palm constitute the gripper, all of which are vacuum actuated. Internal wedges are used to tailor the deformation of a soft outer reinforced skin as vacuum collapses the composite structure. A computational finite-element model is proposed to predict finger kinematics. Thanks to its active palm, the gripper is capable of grasping a wide range of part geometries and compliances while achieving a maximum payload of 30 N. The gripper natural softness enables robust open-loop grasping even when components are not properly aligned. Furthermore, the grasp pose of objects with various aspect ratios and compliances can be robustly maintained during manipulation at linear accelerations of up to 15 m/s2 and angular accelerations of up to 5.23 rad/s2.

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.

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.

The Impact of Simplifications on the Performance of a Finite Element Model of aMacaca fascicularisCranium

2014 ◽  
Vol 298 (1) ◽  
pp. 107-121 ◽  
Author(s):  
Laura C. Fitton ◽  
Miguel PrôA ◽  
Charlie Rowland ◽  
Viviana Toro-ibacache ◽  
Paul O'higgins
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
The Impact
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