• Journal of Biosystems Engineering
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• v.29 no.6 s.107
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• pp.501-507
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• 2004

Fruits we subjected to complex dynamic stresses in the transportation environment. During a long journey from the production area to markets, there is always some degree of vibration present. Vibration inputs are transmitted from the vehicle through the packaging to the fruit. Inside, these cause sustained bouncing of fruits against each other and container wall. These steady state vibration input may cause serious fruit injury, and this damage is particularly severe whenever the fruit inside the package is free to bounce, and is vibrated at its resonant frequency. The determination of the resonant frequencies of the fruit may help the packaging designer to determine the proper packaging system providing adequate protection for the fruit, and to understand the complex interaction between the components of fruit when they relate to expected transportation vibration inputs. The vibration characteristics of the pears in corrugated fiberboard container in transit were analyzed using FEM (finite element method) modeling, and the FEM modeling approach was first validated by comparing the results obtained from simulation and experiment for the pear in the frequency range 3 to 150 Hz and acceleration level of 0.25 G-rms and it was found that between simulated and measured frequencies of the pears have a relatively good agreement. It was observed that the fruit and vegetables in corrugated fiberboard container could be analyzed by finite element method. As the elastic modulus of the cushion materials of corrugated fiberboard pad and tray cup decreased, the first frequencies of upper and lower pears increased and the peak acceleration decreased.

• Elastomers and Composites
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• v.53 no.4
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• pp.207-212
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• 2018

Taylor rod impact tests have been the subject of many theoretical and experimental investigations. This paper discusses the numerical methods for simulating the Taylor impact test, which is widely used to obtain constitutive equations and failure conditions under high-velocity collisions of materials. With this in mind, a particle-based MPM (material point method) for linear viscoelastic solid materials was implemented, and MPM simulations for viscoelastic deformation behavior were numerically verified and confirmed by comparing the MPM and FEM results. In addition, this modeling and numerical approach could be extended to more complex viscoelastic models for basic understanding and to analyze the deformation and fracture behavior of more complicated viscoelastic material systems.

• Journal of the Society of Naval Architects of Korea
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• v.30 no.3
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• pp.90-99
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• 1993

As the finite element method has become a considerable and effective design tool in ship structural analysis, modeling of three dimensional finite element mesh is more necessary than before. However, the unique style and complexity of a ship usually make the modeling be hard and costly. Although most pre-processor of FEM software and geometric modeler provides modeling function, the capability is quite limited for complicated structure. In order to perform FEM modeling quickly, it is necessary to extract, rearrange, and formalize data from ship design database for partially automatic mesh generation. In this paper, the process of designing relational data tables from design data is shown as a part of analysis automation with the application of engineering database concept.

• Transactions of Materials Processing
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• v.18 no.3
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• pp.229-235
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• 2009

This paper covers finite element simulations to evaluate the terminal crimping process of automobile electrical connector. Crimping is a classical technology process to ensure the electrical and the mechanical link between a wire and a terminal. Numerical modeling of the process is helpful to choose and to optimize the dimensions of the crimping part of the connector. In this paper, we discuss a 2D simulation of the crimping process, using explicit finite element methods (ABAQUS/Explicit) and we compare the results with experimental data from the industrial process of crimping (crimping height, crimping width and compressibility). The explicit method is preferred for the modeling of multi-contact problems, in spite of the quasi-static process of crimping. As compared with CAE analysis, a performance improvement makes certain of the truth of the matter.

• Geomechanics and Engineering
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• v.6 no.6
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• pp.593-612
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• 2014

The uplift response of symmetrical square anchor plates has been evaluated in physical model tests and numerical simulations using Plaxis. The behavior of square anchor plates during uplift test was studied by experimental data and finite element analyses in loose sand. Validation of the analysis model was also carried out with 50 mm, 75 mm and 100 mm Length square plates in loose sand. Agreement between the uplift responses from the physical model tests and finite element modeling using PLAXIS 2D, based on 100 mm computed maximum displacements was excellent for square anchor plates. Numerical analysis using square anchor plates was conducted based on the hardening soil model (HSM). The research has shown that the finite element results are higher than the experimental findings in loose sand.

• Computers and Concrete
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• v.21 no.6
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• pp.607-622
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• 2018

A non-linear finite element model (FEM) was constructed using a three-dimensional software (ATENA-3D) to investigate the effect of strengthening on the behavior of prestressed hollow-core (PHC) slabs with or without openings. The slabs were strengthened using near surface mounted (NSM)-carbon fiber reinforced polymer (CFRP) strips. The constructed model was validated against experimental results that were previously reported by the authors. The validated FEM was then used to conduct an extensive parametric study to examine the influence of prestressing reinforcement ratio, compressive strength of concrete and strengthening reinforcement ratio on the behavior of such slabs. The FEM results showed good agreement with the experimental results where it captured the cracking, yielding, and ultimate loads as well as the mid-span deflection with a reasonable accuracy. Also, an overall enhancement in the structural performance of these slabs was achieved with an increase in prestressing reinforcement ratio, compressive strength of concrete, external reinforcement ratio. The presence of openings with different dimensions along the flexural or shear spans reduced significantly the capacity of the PHC slabs. However, strengthening these slabs with 2 and 4 (64 and $128mm^2$ that represent reinforcement ratios of 0.046 and 0.092%) CFRP strips was successful in restoring the original strength of the slab and enhancing post-cracking stiffness and load carrying capacity.

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.647-649
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• 2001

It is a indispensible condition that the simulation and the experiment to improve a efficiency of maglev system. We usually carry out the simulation using the approximate equation, because it is impossible to use a exact modeling such as a practice modeling. This paper proposed a ideal simulation ap to the maglev system modeling by Finite Ele Method. To save the electrical energy, zero p control method is used, and verifying the feasibi FEM dynamic simulation, we make an exper with a TI DSP TMS320F240-based hardware.

• Computers and Concrete
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• v.4 no.2
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• pp.83-100
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• 2007

Applying a direct formulation for the enrichment of the displacement field an extended finite element (XFEM) scheme for modeling of cohesive crack growth is developed. Only elements cut by the crack is enriched and the scheme fits within the framework of standard FEM code. The scheme is implemented for the 3-node constant strain triangle (CST) and the 6-node linear strain triangle (LST). Modeling of standard concrete test cases such as fracture in the notched three point beam bending test (TPBT) and in the four point shear beam test (FPSB) illustrates the performance. The XFEM results show good agreement with results obtained by applying standard interface elements in FEM and with experimental results. In conjunction with criteria for crack growth local versus nonlocal computation of the crack growth direction is discussed.

• Biomaterials and Biomechanics in Bioengineering
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• v.3 no.2
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• pp.71-84
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• 2016

The finite element method is wide used in simulation in the biomechanical structures, but a lack of studies concerning finite element mesh quality in biomechanics is a reality. The present study intends to analyze the importance of the mesh quality in the finite element model results from humeral structure. A sensitivity analysis of finite element models (FEM) is presented for the humeral bone and cartilage structures. The geometry of bone and cartilage was acquired from CT scan and geometry reconstructed. The study includes 54 models from same bone geometry, with different mesh densities, constructed with tetrahedral linear elements. A finite element simulation representing the glenohumeral-joint reaction force applied on the humerus during $90^{\circ}$ abduction, with external load as the critical condition. Results from the finite element models suggest a mesh with 1.5 mm, 0.8 mm and 0.6 mm as suitable mesh sizes for cortical bone, trabecular bone and humeral cartilage, respectively. Relatively to the higher minimum principal strains are located at the proximal humerus diaphysis, and its highest value is found at the trabecular bone neck. The present study indicates the minimum mesh size in the finite element analyses in humeral structure. The cortical and trabecular bone, as well as cartilage, may not be correctly represented by meshes of the same size. The strain results presented the critical regions during the $90^{\circ}$ abduction.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.8
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• pp.790-796
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• 2013

Micro-speaker diaphragms play an important role in generating a desired audio response. The diaphragm is generally a circular membrane, and the cross section is a double dome, with an inner dome and an outer dome. To improve the sound quality of the speaker, a number of corrugations may be included in the outer dome region. In this study, the role of these corrugations is investigated using two kinds of finite element method (FEM) calculations. Structural FEM modeling was carried out to investigate the change in stiffness of the diaphragm when the corrugations were included. Modal FEM modeling was then carried out to compare the natural frequencies and the resulting vibrational modes of the plain and corrugated diaphragms. The effects of the corrugations on the vibration characteristics of the diaphragm are discussed.