• Composites Research
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• v.28 no.1
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• pp.1-5
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• 2015

In this paper the influence of fiber orientation of basalt and carbon inter-ply fabrics on the flexural properties of hybrid composite laminates was experimentally investigated. Four types of basalt/carbon/epoxy inter-ply hybrid composite laminates with varying angle ply orientation of reinforced basalt fiber and fixed orientation of carbon fiber were fabricated using hand lay-up technique. Three point bending test was performed according to ASTM 7264. The fracture surface analysis was carried out by scanning electron microscope (SEM). The results obtained from the four laminates were compared. Lay-up pattern of $[0B/+30B/-30B/0C]_S$ exhibits the best properties in terms of flexural strength and flexural modulus. Scanning electron microscopy results on the fracture surface showed that the interfacial de-bonding between the fibers and epoxy resin is a dominant fracture mode for all fiber lay-up schemes.

• Journal of Fashion Business
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• v.9 no.2
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• pp.143-159
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• 2005

This study was done to provide basic data for clothing design and thus to contribute to the academic development at the clothing and textile area and collar roll line lay down angle variation at collar width on the open collar. The study was composed as tallows: 1. The variation at collar outer wall size increase collar roll line lay down angle size the more Increase. 2. The outer wall and stand height size increase aware at variation collar width at the more Increase. It is desirable that this study will be at help to enchancement of life style in garments and promotion of garments industury by developing the archetype basic collar pattern suitable to Korean women's garments.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.5 s.176
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• pp.1246-1253
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• 2000

Wire ropes are widely used in cable car, suspension bridge and elevator, etc. and there has been a growing need for ropes of large diameter. The theoretical procedures to obtain the stiffness coefficients of wire ropes, using previously reported theory, are programmed and the verification of the program is made. The effects of lay angle on the stiffness of strand are researched and comparisons on stiffness of rope are made according to the lay type. Axial stiffness optimization problems with coupling and torsional stiffness constraints are formulated and the effects of constraints on other stiffness coefficients on axial stiffness optimization are investigated.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.39
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• pp.4.1-4.7
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• 2017

Background: This study is a quantitative evaluation of the influence of the mentolabial angle on perceived attractiveness and threshold values of desire for surgery. Methods: The mentolabial angle of an idealized silhouette male Caucasian profile image was altered incrementally between $84^{\circ}$ and $162^{\circ}$. Images were rated on a Likert scale by pretreatment orthognathic patients (n = 75), lay people (n = 75) and clinicians (n = 35). Results: A mentolabial angle of approximately $107^{\circ}$ to $118^{\circ}$ was deemed the most attractive, with a range of up to $140^{\circ}$ deemed acceptable. Angles above or below this range were perceived as unattractive, and anything outside the range of below $98^{\circ}$ or above $162^{\circ}$ was deemed very unattractive. A deep mentolabial angle ($84^{\circ}$) or an almost flat angle ($162^{\circ}$) was deemed the least attractive. In terms of threshold values of desire for surgery, for all groups, a threshold value of ${\geq}162^{\circ}$ and ${\leq}84^{\circ}$ indicated a preference for surgery, although clinicians were least likely to suggest surgery. The clinician group was the most consistent, and for many of the images, there was some variation in agreement between clinicians and lay people as to whether surgery is required. There was even more variability in the assessments for the patient group. Conclusions: It is recommended that in orthognathic and genioplasty planning, the range of normal variability of the mentolabial angle, in terms of observer acceptance, is taken into account as well as threshold values of desire for surgery. The importance of using patients as observers in attractiveness research is stressed.

• Structural Engineering and Mechanics
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• v.33 no.6
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• pp.657-674
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• 2009

In this paper a 3-D continuum damage mechanics formulation for composite laminates and its implementation into a finite element model that is based on the layer-wise laminate plate theory are described. In the damage formulation, each composite ply is treated as a homogeneous orthotropic material exhibiting orthotropic damage in the form of distributed microscopic cracks that are normal to the three principal material directions. The progressive damage of different angle ply composite laminates under quasi-static loading that exhibit the free edge effects are investigated. The effects of various numerical modeling parameters on the progressive damage response are investigated. It will be shown that the dominant damage mechanism in the lay-ups of [+30/-30]s and [+45/-45]s is matrix cracking. However, the lay-up of [+15/-15] may be delaminated in the vicinity of the edges and at $+{\theta}/-{\theta}$ layers interfaces.

• Proceedings of the Materials Research Society of Korea Conference
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• 1992.05a
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• pp.139-142
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• 1992

• Journal of the Korean Society for Aviation and Aeronautics
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• v.21 no.2
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• pp.7-14
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• 2013

In this paper, the optimal design of composite rotor blade cross-section is performed using a genetic algorithm. Skin thickness, torsion box thickness and skin lay-up angle are adopted as discrete design variables. The position and width of a torsion box are considered as continuous variables. An object function of optimal design is to minimize the mass of a rotor blade, and constraints are failure index, center mass, natural frequency and blade minimum mass per unit length. Finally, design variables such as the thickness and lay-up angles of a skin, and the thickness, position and width of a torsion box are determined by using an in-house program developed for the optimal design of rotor blade cross-section.

• Journal of Aerospace System Engineering
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• v.8 no.1
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• pp.12-17
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• 2014

In this paper, optimal design of composite rotor blade cross-section to consider manufacturability was performed. Skin thickness, torsion box thickness and skin lay-up angle were adopted as discrete design variables and The position and width of a torsion box were considered as continuous variables. An object function of optimal design is to minimize the mass of a rotor blade, and various constraints such as failure index, center mass, shear center, natural frequency and blade minimum mass per unit length were adopted. Finally, design variables such as the thickness and lay-up angles of a skin, and the thickness, position and width of a torsion box were determined by using an in-house program developed for the optimal design of rotor blade cross-section.

• Journal of Satellite, Information and Communications
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• v.11 no.2
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• pp.69-73
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• 2016

In order to derive reliable propagation models for future millimeter-wave frequency indoor pico-cellular communications systems, accurate reflectivity data of building materials is necessary. The broad variety of building materials and construction codes makes accurate attenuation prediction very difficult without the support of specific construction data or measurements. This paper derives a transmission and reflection coefficient based on 13 GHz to 28 GHz measurement data. Transmission and reflection is measured by applying change in the reception angle of each building material, such as plasterboard. The transmission and reflection coefficient derived shows a correlation between frequency dependence and angle. As a result, as the reception angle is reduced, the reflected angle from the transmitter that could be received increases, showing that there is a correlation. In addition, the fundamental investigations carried out lay the foundation for radio channel-related research, which is essential for the development of future millimeter-wave communications systems.

• Advances in Computational Design
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• v.5 no.1
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• pp.55-89
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• 2020

For the first time, an accurate analytical solution, based on coupled three-dimensional (3D) piezoelasticity equations, is presented for free vibration analysis of the angle-ply elastic and piezoelectric flat laminated panels under arbitrary boundary conditions. The present analytical solution is applicable to composite, sandwich and hybrid panels having arbitrary angle-ply lay-up, material properties, and boundary conditions. The modified Hamiltons principle approach has been applied to derive the weak form of governing equations where stresses, displacements, electric potential, and electric displacement field variables are considered as primary variables. Thereafter, multi-term multi-field extended Kantorovich approach (MMEKM) is employed to transform the governing equation into two sets of algebraic-ordinary differential equations (ODEs), one along in-plane (x) and other along the thickness (z) direction, respectively. These ODEs are solved in closed-form manner, which ensures the same order of accuracy for all the variables (stresses, displacements, and electric variables) by satisfying the boundary and continuity equations in exact manners. A robust algorithm is developed for extracting the natural frequencies and mode shapes. The numerical results are reported for various configurations such as elastic panels, sandwich panels and piezoelectric panels under different sets of boundary conditions. The effect of ply-angle and thickness to span ratio (s) on the dynamic behavior of the panels are also investigated. The presented 3D analytical solution will be helpful in the assessment of various 1D theories and numerical methods.