Simplified explicit finite element model for the impact of a wheel on a crossing – Validation and parameter study

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.

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Finite Element Modeling of Unidirectional Non-Crimp Fabric for Manufacturing of Composites with Embedded Cabling

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.554-557.484 ◽

2013 ◽

Vol 554-557 ◽

pp. 484-491 ◽

Cited By ~ 3

Author(s):

Alexander S. Petrov ◽

James A. Sherwood ◽

Konstantine A. Fetfatsidis ◽

Cynthia J. Mitchell

Keyword(s):

Finite Element ◽

Finite Element Model ◽

Element Model ◽

Explicit Finite Element ◽

Shell Elements ◽

Beam Elements ◽

Hybrid Finite Element ◽

International Benchmarking ◽

Unidirectional Glass ◽

Forming Simulations

A hybrid finite element discrete mesoscopic approach is used to model the forming of composite parts using a unidirectional glass prepreg non-crimp fabric (NCF). The tensile behavior of the fabric is represented using 1-D beam elements, and the shearing behavior is captured using 2-D shell elements into an ABAQUS/Explicit finite element model via a user-defined material subroutine. The forming of a hemisphere is simulated using a finite element model of the fabric, and the results are compared to a thermostamped part as a demonstration of the capabilities of the used methodology. Forming simulations using a double-dome geometry, which has been used in an international benchmarking program, were then performed with the validated finite element model to explore the ability of the unidirectional fabric to accommodate the presence of interlaminate cabling.

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

International Journal of Protective Structures ◽

10.1177/2041419618776332 ◽

2018 ◽

Vol 9 (4) ◽

pp. 504-524 ◽

Cited By ~ 5

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.

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Numerical and Experimental Investigation on the Energy Absorption Capability of a Full-Scale Composite Fuselage Section

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.827.19 ◽

2019 ◽

Vol 827 ◽

pp. 19-24 ◽

Cited By ~ 3

Author(s):

Donato Perfetto ◽

Giuseppe Lamanna ◽

M. Manzo ◽

A. Chiariello ◽

F. di Caprio ◽

...

Keyword(s):

Finite Element ◽

Energy Absorption ◽

Load Condition ◽

Element Model ◽

Full Scale ◽

Research Centre ◽

Fe Method ◽

Explicit Finite Element ◽

Crashworthiness Design ◽

The Impact

In the case of catastrophic events, such as an emergency landing, the fuselage structure is demanded to absorb most of the impact energy preserving, at the same time, a survivable space for the passengers. Moreover, the increasing trend of using composites in the aerospace field is pushing the investigation on the passive safety capabilities of such structures in order to get compliance with regulations and crashworthiness requirements. This paper deals with the development of a numerical model, based on the explicit finite element (FE) method, aimed to investigate the energy absorption capability of a full-scale 95% composite made fuselage section of a civil aircraft. A vertical drop test, performed at the Italian Aerospace Research Centre (CIRA), carried out from a height of 14 feet so to achieve a ground contact velocity of 30 feet/s in according to the FAR/CS 25, has been used to assess the prediction capabilities of the developed FE method, allowing verifying the response under dynamic load condition and the energy absorption capabilities of the designed structure. An established finite element model could be used to define the reliable crashworthiness design strategy to improve the survival chance of the passengers in events such as the investigated one.

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Surface Formation Study Using a 3-D Explicit Finite Element Model of Machining of Gray Cast Iron

Procedia CIRP ◽

10.1016/j.procir.2016.02.168 ◽

2016 ◽

Vol 45 ◽

pp. 111-114 ◽

Cited By ~ 3

Author(s):

Kyle Odum ◽

Masakazu Soshi

Keyword(s):

Finite Element ◽

Cast Iron ◽

Finite Element Model ◽

Gray Cast Iron ◽

Element Model ◽

Gray Cast ◽

Surface Formation ◽

Explicit Finite Element

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Parameter study on a finite element model of the middle ear / Parameterstudie an einem Finite-Elemente-Modell des Mittelohrs

Biomedical Engineering / Biomedizinische Technik ◽

10.1515/bmt.2010.006 ◽

2010 ◽

Vol 55 (1) ◽

pp. 19-26 ◽

Cited By ~ 9

Author(s):

Marc Hoffstetter ◽

Florian Schardt ◽

Thomas Lenarz ◽

Sabine Wacker ◽

Erich Wintermantel

Keyword(s):

Finite Element ◽

Finite Element Model ◽

Middle Ear ◽

Element Model ◽

Parameter Study ◽

Finite Elemente

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

Journal of Biomechanical Engineering ◽

10.1115/1.4045808 ◽

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.

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Characterization of Adhesives Bonding in Aircraft Structures

Materials ◽

10.3390/ma13214816 ◽

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.

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