Ballistic Impact of Single Particles Into Gelatin: Experiments and Modeling With Application to Transdermal Pharmaceutical Delivery

2010 ◽  
Vol 132 (10) ◽  
Author(s):  
R. A. Guha ◽  
N. H. Shear ◽  
M. Papini
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
High Speed ◽  
Element Model ◽  
Powder Injection ◽  
Single Particles ◽  
Human Dermis ◽  
Injection Technology ◽  
Penetration Behavior ◽  
The Impact

The impact and penetration of high speed particles with the human skin is of interest for targeted drug delivery by transdermal powder injection. However, it is often difficult to perform penetration experiments on dermal tissue using micron scale particles. To address this, a finite element model of the impact and penetration of a 2 μm gold particle into the human dermis was developed and calibrated using experiments found in the literature. Using dimensional analysis, the model was linked to a larger scale steel ball-gelatin system in order to extract key material parameters for both systems and perform impact studies. In this manner, an elastic modulus of 2.25 MPa was found for skin, in good agreement with reported values from the literature. Further gelatin experiments were performed with steel, polymethyl methacrylate, titanium, and tungsten carbide balls in order to determine the effects of particle size and density on penetration depth. Both the finite element model and the steel-gelatin experiments were able to predict the penetration behavior that was found by other investigators in the study of the impact of typical particles used for vaccine delivery into the human dermis. It can therefore be concluded that scaled up systems utilizing ballistic gelatins can be used to investigate the performance of transdermal powder injection technology.

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.

Simulation and Experimental Research on Milling Force of High Manganese Steel

2010 ◽  
Vol 143-144 ◽  
pp. 863-867
Author(s):  
Yong Tang ◽  
Qiang Wu ◽  
Xiao Fang Hu ◽  
Yu Zhong Li
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
High Speed ◽  
Shear Failure ◽  
Element Model ◽  
Manganese Steel ◽  
High Manganese ◽  
Milling Force ◽  
High Manganese Steel ◽  
High Speed Milling

The milling process of hard-to-cut material high manganese steel ZGMn13 was simulated and experimental studied based on Johnson-Cook material model and shear failure model.The high speed milling processing finite element model has established adopting arbitrary Lagrangian-Euler method (ALE) and the grid adaptive technology,The influence of milling parameters to milling force is analyzed in the high speed milling high manganese steel process. The simulated and experimental results being discussed are matched well. It certifies the finite element model is correct.

Validation of a New Finite Element Model for Human Knee Ligaments for Use in High Speed Automotive Collisions

2009 ◽  
Author(s):  
Chiara Silvestri ◽  
Louis R. Peck ◽  
Kristen L. Billiar ◽  
Malcolm H. Ray
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Strain Rate ◽  
High Speed ◽  
Element Model ◽  
Knee Ligament ◽  
Knee Ligaments ◽  
Human Knee ◽  
Dynamic Representation ◽  
Failure Properties

A finite element model of knee human ligaments was developed and validated to predict the injury potential of occupants in high speed frontal automotive collisions. Dynamic failure properties of ligaments were modeled to facilitate the development of more realistic dynamic representation of the human lower extremities when subjected to a high strain rate. Uniaxial impulsive impact loads were applied to porcine medial collateral ligament-bone complex with strain rates up to145 s−1. From test results, the failure load was found to depend on ligament geometric parameters and on the strain rate applied. The information obtained was then integrated into a finite element model of the knee ligaments with the potential to be used also for representation of ligaments in other regions of the human body. The model was then validated against knee ligament dynamic tolerance tests found in literature. Results obtained from finite element simulations during the validation process agreed with the outcomes reported by literature findings encouraging the use of this ligament model as a powerful and innovative tool to estimate ligament human response in high speed frontal automotive collisions.

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.

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