• Structural Engineering and Mechanics
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• 제10권4호
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• pp.393-404
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• 2000

Linear stress analysis without body force can be easily solved by means of the boundary element method. Some cases of linear stress analysis with body force can also be solved without a domain integral. However, domain integrals are generally necessary to solve the linear stress problem with arbitrary body forces. This paper shows that the linear stress problem with arbitrary body forces can be solved approximately without a domain integral by the triple-reciprocity boundary element method. In this method, the distribution of arbitrary body forces can be interpolated by the integral equation. A new computer program is developed and applied to several problems.

• 대한기계학회논문집A
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• 제21권11호
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• pp.1844-1851
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• 1997

Displacement fields and interface stresses are obtained by modifying the potential energy functional with a penalty function which enforces the continuity of stresses at the interface of two-materials. Based on the displacement field and the interface stresses, a new methodology to generate a continuous stress field over the entire domain including the interface of the dissimilar materials has been proposed by combining the L$^{2}$ projection method of stress-smoothing and the Loubignac's iterative method of improving the displacement field. Stress analysis was carried out on two examples which are made of highly dissimilar materials. As a result of the analysis, it is found that the proposed method provides improved continuity of the stress field over the entire domain as well as predicting accurate nodal stresses at the interface. In contrast, the conventional displacement-based finite element method provides significant stress discontinuties at the interfaces. In addition, it was found that the total strain energy evaluated from the improved continuous stress field converge to the exact value as increasing the number of iterations in the proposed method.

• Child Health Nursing Research
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• 제10권4호
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• pp.423-430
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• 2004

Purpose: The main purposes of this descriptive survey study were to describe parenting stress and needs of mothers of children with atopic dermatitis. Method: Data were collected from 111 mothers of children under 6 year-old with atopic dermatitis registered at one university affiliated medical center in Seoul. The instruments used for this study were a self-report questionnaire, Parenting Stress Index (PSI) Short Form by Abidin, and an open question to identify nursing needs. Descriptive analysis, Pearson correlation and contents analyses were done. Result: The mean score for parenting stress was 77.25 (range: 12-60), for parent domain 31.50 (range: 12-60), parent-child domain 21.02 (range: 11-55) and child domain was 24.72 (range: 11-51). There was a significant positive relationship between parenting stress and severity of symptom (r=0.192, p<.005). The maternal stressors included extra housework related to symptom management, treatment related to atopic dermatitis, personality and behavior of child, and financial problems. Conclusion: the mothers of children with atopic dermatitis have high parenting stress from various stressors and needs. It is recommended that nursing interventions should include stress management and take into consideration the educational needs of mothers.

• 한국정밀공학회지
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• 제22권2호
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• pp.113-119
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• 2005

A crack emanating from an internal electrode or a conducting damage path in ferroelectric ceramic actuators is analyzed. The boundary of the domain switching zone near the edge of the internal electrode in a ceramic multilayer actuator is determined based on the nonlinear electric theory. The stress intensity factor induced by a ferroelectric domain switching under small scale conditions is numerically obtained for flaws of various sizes near the electrode edge. It is found that stress intensity factor near the crack tip depends on the material property of the electrical nonlinearity.

• Advances in materials Research
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• 제13권5호
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• pp.417-429
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• 2024

The research paper is devoted to study of the thermomechanical deformations occurring in a nonlocal homogeneous isotropic thick circular plate with frequency domain and without energy dissipation. The upper and lower surfaces of the thick circular plate are traction free subjected to axisymmetric heatsupply. Hankel transform has been used to find the analytical solutions. The expressions for physical quantities such as displacement components, stress components and conductive temperature have been obtained in the transformed domain. The resulting quantities in the physical domain have been obtained by using the numerical inversion technique. The numerical simulated results have been depicted graphically to study the effect of nonlocality and two temperature on the components of displacement, stress components and conductive temperature.

• Steel and Composite Structures
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• 제46권3호
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• pp.435-449
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• 2023

Time domain method and frequency domain method are commonly used in the current fatigue life calculation theory. The time domain method has complicated procedures and needs a large amount of calculation, while the frequency domain method has poor applicability to different materials and different spectrum, and improper selection of spectrum model will lead to large errors. Considering that artificial neural network has strong ability of nonlinear mapping and generalization, this paper applied this technique to random fatigue life prediction, and the effect of average stress was taken into account, thereby achieving more accurate prediction result of random fatigue life.

• Coupled systems mechanics
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• 제9권6호
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• pp.521-538
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• 2020

The present study is concerned with the thermoelastic interactions in a two dimensional homogeneous, transversely isotropic thermoelastic solid with new modified couple stress theory without energy dissipation and with two temperatures in frequency domain. The time harmonic sources and Hankel transform technique have been employed to find the general solution to the field equations.Concentrated normal force, normal force over the circular region, thermal point source and thermal source over the circular region have been taken to illustrate the application of the approach. The components of displacements, stress, couple stress and conductive temperature distribution are obtained in the transformed domain. The resulting quantities are obtained in the physical domain by using numerical inversion technique. Numerically simulated results are depicted graphically to show the effect of angular frequency on the resulted quantities.

• Coupled systems mechanics
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• 제8권6호
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• pp.501-522
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• 2019

The present study is concerned with the thermoelastic interactions in a two dimensional axisymmetric problem in transversely isotropic thermoelastic solid using new modified couple stress theory without energy dissipation and with two temperatures. The Laplace and Hankel transforms have been employed to find the general solution to the field equations. Concentrated normal force, normal force over the circular region, concentrated thermal source and thermal source over the circular region have been taken to illustrate the application of the approach. The components of displacements, stress, couple stress and conductive temperature distribution are obtained in the transformed domain. The resulting quantities are obtained in the physical domain by using numerical inversion technique. The effect of two temperature varying by taking different values for the two temperature on the components of normal stress, tangential stress, conductive temperature and couple stress are depicted graphically.

• 한국전기전자재료학회논문지
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• 제18권3호
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• pp.248-252
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• 2005

The effects of electric field strength and mechanical compressive stress on the displacement of multilayered ceramic actuator, stacked alternatively 0.2 (PbM $n_{1}$3/N $b_{2}$3/ $O_3$)-0.8(PbZ $r_{0.475}$ $Ti_{0.525}$ $O_3$) ceramic thin films and 70Ag-30Pd electrodes were investigated. Because the actuators were designed to stack ceramic layer and electrode layer alternatively, the ceramic-electrode interfaces may act as a resistance to motion of domain wall. so the polarization and strain were affected by the amount of 180$^{\circ}$domain, electric field strength and mechanical compressive stress. Consequently, the change of polarization, displacement with respect to field strength, and mechanical compressive stress were likely to be caused by readiness of the domain wall movement around the ceramic-electrode interfaces.ces.

• 한국세라믹학회지
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• 제26권1호
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• pp.37-42
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• 1989

Periodic layered domain structures in doped LiNbO3 crystals grown by Czochralski method were obtained by thermal fluctuation and crystal rotation with inhomogeneous radial temprature distribution. The stressinduced domain formation mechanism model was suggested and discussed.