• Structural Engineering and Mechanics
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• v.57 no.4
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• pp.733-762
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• 2016

Based on a reduced displacement field, a layer-wise (LW) formulation is developed for analysis of thick shell panels which is subjected to axial tension. Employing the principle of minimum total potential energy, the local governing equations of thick panel which is subjected to axial extension are obtained. An analytical method is developed for solution of the governing equations for various edge conditions. The governing equations are solved for free and simply supported edge conditions. The interlaminar stresses in the panel are investigated by means of Hooke's law and also by means of integration of the equilibrium equations of elasticity. Dependency of the result upon the number of numerical layers in the layerwise theory (LWT) is studied. The accuracy of the numerical results is validated by comparison with the results of the finite element method and with other available results in the open literature and good agreement is seen between the results. Numerical results are then presented for the distribution of interlaminar normal and shear stresses within the symmetric and un-symmetric cross-ply thick panels with free and simply supported boundaries. The effects of the geometrical parameters such as radius to thickness and width to thickness ratio are investigated on the distribution of the interlaminar stresses in thick panels.

• The korean journal of orthodontics
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• v.41 no.5
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• pp.324-336
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• 2011

Objective: The aim of this study was to conduct three-dimensional finite element analysis of individual tooth displacement and stress distribution when a posterior retraction force of 200 g was applied at different positions of the retraction hook on the transpalatal arch (TPA) of a molar, and over different lengths of the lever arm on the maxillary anterior teeth in lingual orthodontics. Methods: A three-dimensional finite element model, including the entire upper dentition, periodontal ligaments, and alveolar bones, was constructed on the basis of a sample (Nissan Dental Product, Kyoto, Japan) survey of Asian adults. Individual movement of the incisal edge and root apex was estimated along the x-, y-, and z-coordinates to analyze tooth displacement and von Mises stress distribution. Results: When the length of the lever arm was 15 mm and 20 mm, the incisal edge and root apex of the anterior teeth was displaced lingually, with a maximum lingual displacement at the lever arm length of 20 mm. When the posterior retraction hook was on the root apex, the molars showed distal displacement. When the length of the lever arm was 20 mm, anterior extrusion was reduced and the crown of the canine displaced toward the buccal side, in which case, the retraction hook was on the edge, rather than at the center, of the TPA. Conclusions: The results of the analysis showed that when 6 anterior teeth were retracted posteriorly, lateral displacement of the canine and lingual displacement of the incisal edge and root apex of the anterior teeth occur without the extrusion of the anterior segment when the length of the lever arm is longer, and the posterior retraction hook is in the midpalatal area.

• Structural Engineering and Mechanics
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• v.29 no.6
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• pp.623-642
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• 2008

While spatial plastic mechanism analysis has been widely and successfully applied to thinwalled steel structures to analyse the post-failure behaviour of sections and connections, there remains some contention in the literature as to the basic capacity of an inclined yield line. The simple inclined hinge commonly forms as part of the more complex spatial mechanism, which may involve a number of hinges perpendicular or inclined to the direction of thrust. In this paper some of the existing theories are compared with single inclined yield lines that form in flange outstands, by comparing the theories with plate tests of plates simply supported on three sides with the remaining (longitudinal) edge free. The existing mechanism theories do not account for different in-plane displacement gradients of the loaded edge, nor the slenderness of the plates, and produce conservative results. A modified theory is presented whereby uniform and non-uniform in-plane displacements of the loaded edge of the flange, and the slenderness of the flange, are accounted for. The modified theory is shown to compare well with the plate test data, and its application to flanges that are components of sections in compression and/or bending is presented.

• Coupled systems mechanics
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• v.1 no.1
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• pp.59-78
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• 2012

The available analytical methods of analysis for laterally loaded piles in level ground cannot be directly applied to such piles in sloping ground. With the commercially available software, the simulation of the appropriate field condition is a challenging task, and the results are subjective. Therefore, it becomes essential to understand the process of development of a user-framed numerical formulation, which may be used easily as per the specific site conditions without depending on other indirect methods of analysis as well as on the software. In the present study, a detailed three-dimensional finite element formulation is presented for the analysis of laterally loaded piles in sloping ground developing the 18 node triangular prism elements. An application of the numerical formulation has been illustrated for the pile located at the crest of the slope and for the pile located at some edge distance from the crest. The specific examples show that at any given depth, the displacement and bending moment increase with an increase in slope of the ground, whereas they decrease with increasing edge distance.

• Steel and Composite Structures
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• v.1 no.2
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• pp.201-212
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• 2001

In order to investigate the effect of the loading rate on the mechanical behavior of SRC shearwalls, we conducted the lateral loading tests on the 1/3 scale model shearwalls whose edge columns were reinforced by H-shaped steel. The specimens were subjected to the reversed cyclic lateral load under a variable axial load. The two types of loading rate, 0.01 cm/sec for the static loading and 1 cm/sec for the dynamic loading were adopted. The failure mode in all specimens was the sliding shear of the in-filled wall panel. The edge columns did not fail in shear. The initial lateral stiffness and lateral load carrying capacity of the shearwalls subjected to the dynamic loading were about 10% larger than those subjected to the static loading. The effects of the arrangement of the H-shaped steel on the lateral load carrying capacity and the lateral load-displacement hysteresis response were not significant.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.05a
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• pp.215-220
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• 2001

The objective of this study is to examine the fracture characteristics of concrete at early ages such as critical stress intensity factor, critical crack-tip opening displacement, fracture energy based on the concepts of the effective-elastic crack model and the cohesive crack model. A wedge splitting test for Mode I was performed on cubic wedge specimens with a notch at the edge. By varying strength and age, load-crack mouth opening displacement curves were obtained and the results were analyzed by linear elastic fracture mechanics. The results from the test and analysis showed that critical stress intensity factor and fracture energy increased, and critical crack-tip opening displacement decreased with concrete age from 1 day to 28 days. The obtained fracture parameters at early ages may be used as a fracture criterion and an input data for finite element analysis of concrete at early ages.

• Proceedings of the KWS Conference
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• 2002.10a
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• pp.463-468
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• 2002

This study investigates the variations of shear force, displacement, and fracture surface with the shear speed and the number of reflows. The experimental data of shear tests indicate that the shear force increases as increasing the number of reflows and the shear speed due to the formation of a kind of intermetallic compound, Ni$_3$Sn$_4$, on Au/Ni/Cu pad, and the work-hardening. However, general trends show that the shear force decreases due to increasing the thickness of the intermetallic compound over 4x reflow. It is observed that the intermetallic compound which is formed between solder and pad increases according to increasing the number of reflows, and the growth rate of the intermetallic compound at central region on the interface is faster than one at edge part. The general tendencies of shear force and displacement with different shear speeds are almost identical as an increase of the number of reflows.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.987-991
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• 2003

Ferrule is widely used as fiber optic connecters. In fiber-optic communications, the shape accuracy such as coaxiality and cylindricity of ferrule affects insertion loss. When coaxial grinding of ferrule supported by two pin, pin alignment and chucking accuracy are very important. In this research, the kinematic behavior of the ferrule center is investigated in the case where cone-shaped center pins and round circle holes which make contact with each other near the edge of the holes, using homeogenous coordinate transformation and numerical analysis. The obtained results are as follows: The alignment errors between center holes cause a sinusoidal displacement of ferrule. And the maximum displacement of ferrule centers increase in proportion to the center pin angle. The relationship between center pins displacement in coaxial grinding and grinding accuracy was explained.

• Computers and Concrete
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• v.1 no.3
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• pp.227-248
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• 2004

A combined experimental-computational study of a double edge-notched stone specimen subjected to tensile loading is presented. In the experimental part, the load-deformation response and the displacement field around the crack tip are recorded. An Electronic Speckle Pattern Interferometer (ESPI) is used to obtain the local displacement field. The experimental results are used to validate a numerical model for the description of fracture using finite elements. The numerical model uses displacement discontinuities to model cracks. At the discontinuity, a plasticity-based cohesive zone model is applied for monotonic loading and a combined damage-plasticity cohesive zone model is used for cyclic loading. Both local and global results from the numerical simulations are compared with experimental data. It is shown that local measurements add important information for the validation of the numerical model. Consequently, the numerical models are enhanced in order to correctly capture the experimentally observed behaviour.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.11a
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• pp.184-187
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• 2000

In this paper, a ring-type ultrasonic motor divided into 12 sectors was modeled by Atila program using finite element method(FEM). The stator consists of a piezoelectric ceramic poled alternately in opposite directions and elastic material. And the stator dimension was $\Phi$40 (outer diameter), $\Phi$ 30(inner diameter), 0.5mm(ceramic thickness) and 3mm(elastic material thickness). As a simulation result, 6$\lambda$ displacement occurred at approximately 52kHz, and this resonance frequency is similar to calculated result 57kHz. The position of maximum displacement was at the edge of stator.