Sleeve Length Research Articles

Matrix-graded and fibre-steered composites to tackle stress concentrations

This paper studies the feasibility of improving structural performance of composites in the presence of stress concentrators. Matrix grading through local deposition of additive-enhanced matrices and fibre steering by varying fibrous architecture are examined independently and in combination on a glass-fibre triaxial braided composite subjected to open hole tensile test. Stiffened and toughened matrices were incorporated through precise point-wise injections of liquid reactive resin into dry preforms (Liquid Resin Printing). Fibre steering was implemented by varying the braiding angle along the length of the braided sleeve. It has been shown that these novel forms of architecture modification enable a significant improvement in composite strength through a variety of deformation mechanisms. This includes local stiffening of composite in the direct vicinity of the stress concentrator and damage accumulation away from the stress concentrators. The experimental observations are explained by using simple finite-element models.

Stability and moment-rotation behavior of cold-formed steel purlins with sleeved bolted connection

Long runs of cold-formed steel Z-section purlins are often segmented due to assemblage and transportation issues. The segments are commonly connected by bolts to a short cold-formed steel member similar to the purlin; this short member is typically called a sleeve; from a structural point of view, it does not guarantee a state of full continuity to the purlin. This study reports a series of 15 experiments on cold-formed steel Z-sections purlins with sleeved bolted connections tested in bending. These experiments vary cross-section height, thickness and length of sleeve, and span. This parametric experimental study seeks to better understand the flexural-buckling strength, collapse mechanism, and moment-rotation behavior of purlin-sleeve systems. Since the design of purlins with sleeved bolted connections is often limited by the serviceability limit state, in this case excessive displacement, special attention is given to accurately determining and understanding the moment-rotation behavior of purlin-sleeve systems. Based on the experimental results, an expression is proposed to predict non-linear moment-rotation behavior; the proposed expression is compared to expressions previously proposed in the literature. The proposed moment-rotation expression, when used in a simple rotation spring-beam model, leads to accurate prediction of displacement and bending moment in the purlin-sleeve system at any load stage.

3D 바디 스캐닝을 활용한 20~30대 남성의 자켓 맞음새 만족도

The study purpose was to investigate the jacket-fit satisfaction level of men in their 20s and 30s, using body-scanning data and a questionnaire. Thirty-five men were scanned using a 3D body scanner. The participants were divided into three groups (Small, Medium, and Large) based on their chest-circumference measurement. Their levels of satisfaction with the fit of their tailored jacket were compared by group. Chest, waist, and hip circumferences increased substantially as group size increased. The M-group was mostly satisfied with all body-site views. The S-group was especially dissatisfied with height, back width, waist circumference, and upper-arm circumference. The L-group was especially dissatisfied with waist circumference and hip circumference. The majority of the participants preferred the jacket closely fitted to their body. More than half of the participants thought finding a jacket of suitable size was difficult. When purchasing ready-to-wear jackets, the S-group and the M-group considered shoulder width important, while the L-group considered chest circumference the most important area. When evaluating the fit of ready-to-wear jackets, the L-group evaluated chest circumference, back width, and waist circumference as poor fits. The M-group evaluated sleeve length and shoulder width as poor fits, and the S-group agreed with respect to sleeve length. Body-satisfaction levels and matching jacket-satisfaction levels differed by body-size group, as did areas that need improvement. The conclusion is that size-group analysis using 3D body scanning can be utilized effectively for jacket-fit analysis. The findings of the current study can be applied to improving jacket fit among young male consumers.

Failure and stress analysis of internal pressurized composite pipes joined with sleeves

Failure and stress analyses were carried out for composite pipes adhesively joined with sleeves subjected to internal pressure. In the study, the composite pipes and sleeves were E glass fiber/epoxy with different fiber orientation angles. Circular pieces cut from four layered composite pipes with different orientation angle were used as sleeves. Composite pipes with different orientation angle were bonded using DP410 and DP490 type adhesives. The codes of a numerical model were generated via ANSYS software package for the numerical analyses, and the numerical results were verified using experimental results. The problems were analyzed by using a calculation method based on finite elements method (FEM). The finite element analyses (FEA) were carried out to predict the failure internal pressure. Radial, tangential, axial and shear stress values were obtained via numerical analyses for composite pipes and adhesive layers in the thickness direction. In addition, Von–Mises stress distributions that develop on the adhesive were obtained as well. The effects of orientation angle, sleeve length and adhesive type on strength of composite pipe and bonded zone were examined. The results showed that the adhesive type has higher effect on the strength of bonded composite pipes when compared with orientation angle and sleeve length. In addition, increase in sleeve length increased the failure internal pressure.

A Growth-Accommodating Implant for Paediatric Applications.

Medical implants of fixed size cannot accommodate normal tissue growth in children, and often require eventual replacement or in some cases removal, leading to repeated interventions, increased complication rates and worse outcomes. Implants that can correct anatomic deformities and accommodate tissue growth remain an unmet need. Here, we report the design and use of a growth-accommodating device for paediatric applications that consists of a biodegradable core and a tubular braided sleeve, with inversely related sleeve length and diameter. The biodegradable core constrains the diameter of the sleeve, and gradual core degradation following implantation enables sleeve and overall device elongation in order to accommodate tissue growth. By using mathematical modeling and ex vivo experiments using harvested swine hearts, we demonstrate the predictability and tunability of the behavior of the device for disease- and patient-specific needs. We also used the rat tibia and the piglet heart valve as two models of tissue growth to demonstrate that polymer degradation enables device expansion and growth accommodation in vivo.

Utjecaj dužine cjevastog spoja na deformacijska svojstva injektiranih spojeva

Utjecaj dužine cjevastog spoja na deformacijska svojstva injektiranih spojeva

Connection performance of restrained deformed grouted sleeve splice

Grouted reinforcement sleeve connection is one of the main methods to connect steels. In this article, to investigate the mechanical mechanism and behavior of grouted sleeve splices, six large-diameter grouted sleeve splices were manufactured. The connection property, failure mode, bearing capacity, damage distribution, and hoop confining mechanism were investigated through uniaxial tensile test. The performance of grouted sleeve splices was evaluated according to several indexes of quantification. It was shown that the tensile strength of the sleeve splice is equal to the tensile strength of the steel bar with an embedded length of eight times the bar diameter. Severe damage occurred at the end of the cementitious grout, with the damage depth about 8% of the total sleeve length. Based on the test results, an empirical expression of hoop confining strain along the axis direction of sleeve was proposed. The yield ratio and strength ratio of sleeve splices meet the standard requirements, and the sleeve capacity ratio varies with different bar diameter. The ductility ratio of grouted sleeve splices was all more than 4%, which could meet the earthquake-resistant need in low-moderate seismic regions.

Experimental studies on behaviour of tubular T-joints reinforced with grouted sleeve

Tubular joints have been widely used in offshore platforms and space structures due to their merits such as easy fabrication, aesthetic appearance and better static strength. For existing tubular joints, a grouted sleeve reinforced method was proposed in this paper. Experimental tests on five tubular T-joints reinforced with the grouted sleeve and two conventional tubular T-joints were conducted to investigate their mechanical behaviour. A constant axial compressive force was applied to the chord end to simulate the compressive state of the chord member during the tests. Then an axial compressive force was applied to the top end of the brace member until the collapse of the joint specimens occurred. The parameters investigated herein were the grout thickness, the sleeve length coefficient and the sleeve construction method. The failure mode, ultimate load, initial stiffness and deformability of these joint specimens were discussed. It was found that: (1) The grouted sleeve could change the failure mode of tubular T-joints. (2) The grouted sleeve was observed to provide strength enhancement up to 154.3%~172.7% for the corresponding un-reinforced joint. (3) The initial stiffness and deformability were also greatly improved by the grouted sleeve. (4) The sleeve length coefficient was a key parameter for the improved effect of the grouted sleeve reinforced method.

Mechanical Stability of the Taper Connection of Large Metal Femoral Heads With Adapter Sleeves in Total Hip Arthroplasty Analyzed Using Explicit Finite Element Simulations

BackgroundLarge diameter heads (LDHs) of metal-on-metal bearings in total hip arthroplasty provide increased range of motion and reduced dislocation rates. However, major concerns grew over high wear rates from the modular connection between femoral stem and head, especially in combination with adapter sleeves. MethodsA computational study on the taper connection stability of LDH (50 mm) with adapter sleeves of different lengths (S, M, L, and XL) compared with a standard femoral head (32 mm) without adapter sleeves was conducted using explicit finite element analyses. Four different impact configurations were considered resulting from varied mallet mass (0.5 vs 1.0 kg) and velocity (1.0 vs 2.0 m/s). The taper stability was evaluated by determination of the pull-off forces and micromotions due to simulated joint loads during walking (2 kN and 7.9 Nm, respectively). Moreover, the deformations of the adapter sleeves and the contact area in the taper connections were evaluated. ResultsAlthough the pull-off forces of the LDH with different-sized adapter sleeves were comparable, contact area decreased and adapter sleeve deformations increased (up to 283%) with an increasing adapter sleeve length. Moreover, the micromotions of LDH with adapter sleeves were up to 7-times higher, as compared with the standard femoral head without an adapter sleeve. ConclusionThe present numerical study confirms that the assembly technique of LDH with adapter sleeves reveals increased micromotions compared with standard femoral head sizes. We could demonstrate that deviations of the stem trunnion geometry and improper surgical instructions led to worse mechanical stability of the taper connection.

Calculation method of locking torque based on elastic thin shell theory for hydraulic locking sleeve

The hydraulic locking sleeve is a key component of precision instruments such as five-axis machine tools, giant astronomical telescope, and satellite antenna. This is subjected to the action of pressure load causing large elastic deformation and locking the rotational freedom of feed shaft at any angle. The maximum locking torque is an important parameter for designing the hydraulic locking sleeve. First, the hydraulic locking sleeve is simplified as elastic thin cylindrical shell structure. Neglecting the bending and twisting effects, the calculation equations describing the deformation and stress state between the hydraulic locking sleeve and rotary shaft are derived by applying the theory of elastic thin shell. Then, taking into account that one end of the hydraulic lock sleeve is fixed to the shaft sleeve seat by the end face flange; the calculating formula of the maximum locking torque of the hydraulic locking sleeve is obtained by modifying the deformation equation based on moment model. Finally, a test platform of hydraulic locking sleeve is designed, which can measure the maximum locking torque of the hydraulic locking sleeve. The error between the calculation result of locking torque theoretical calculation model and the experimental measured value is <15%. As a result, the causes of the error are analyzed, and the effects of the shaft sleeve length, wall thickness, and radius on the maximum locking torque are calculated.

Experimental investigation of the effect of insulator sleeve length on the time to pinch and multipinch formation in the plasma focus facility

The length of insulator sleeve is varied to investigate its effect on the pinch formation in the plasma focus facility. In this paper, the effect of insulator length on the time to pinch at various pressures and working voltages in the 1.15 kJ Mather type plasma focus is investigated. The results show that with 4.5 cm insulator length the time to pinch at all pressures is minimum. Other results also confirm that with increasing of pressure the time to pinch is increased. Moreover, with increasing working voltage the time to pinch is decreased. Pictures, captured using a digital single lens reflex (DSLR) Canon EOS 7D system, show that multipinch phenomenon is formed.

한국 남자 군인 현 방한복의 치수, 동작적합성 만족도에 관한 연구

This study investigates the problems of fitness and motion suitability for Korean male military winter jackets (inner and outer) and provides data for new pattern development. We analyzed fitness and motion suitability by a questionnaire survey with 140 Korean male soldiers and a wearing evaluation with 7 subjects of central army male size. A survey of male soldiers indicated that the fitness and motion suitability satisfaction was over 3.0 (Likert scale) for both inner and outer jackets. There were opinions that the sleeve length was short for the inner jacket and the waist girth and hem girth was slightly large for the outer jacket. In the wearing evaluation results with subjects of central army male size, fitness of total length, sleeve length and collar height showed a score lower than 3.0 for the inner jacket and collar height on the outer jacket. The motion suitability result showed a low score (1.0-2.0) in an arm raising motion for the inner jacket and 2.0-3.0 at neck motion in the outer jacket. In conclusion, there is more dissatisfaction in inner jackets than outer jackets. For the inner jacket, sleeve is short, sleeve hem is narrow, collar height is a little high and the sleeve creeps up during arm motion. The waist girth and hem girth was slightly large and collar height was a little high for the outer jacket.

Effects of pile geometry on bearing capacity of open-ended piles driven into sands

Bearing capacity of open-ended piles depends largely on inner frictional resistance, which is influenced by the degree of soil plugging. While a fully-plugged open-ended pile produces a bearing capacity similar to a closed-ended pile, fully coring (or unplugged) pile produces a much smaller bearing capacity. In general, open-ended piles are driven under partially-plugged mode. The formation of soil plug may depend on many factors, including wall thickness at the pile tip (or inner pile diameter), sleeve height of the thickened wall at the pile tip and relative density. In this paper, we studied the effects of wall thickness at the pile base and sleeve height of the thickened wall at the pile tip on bearing capacity using laboratory model tests. The tests were conducted on a medium dense sandy ground. The model piles with different tip thicknesses and sleeve heights of thickened wall at the pile tip were tested. The results were also discussed using the incremental filling ratio and plug length ratio, which are generally used to describe the degree of soil plugging. The results showed that the bearing capacity increases with tip thickness. The bearing capacity of piles of smaller sleeve length (e.g., ≥ 1D; D is pile outer diameter) was found to be dependent on the sleeve length, while it is independent on the sleeve length of greater than a 1D length. We also found that the soil plug height is dependent on wall thickness at the pile base. The results on the incremental filling ratio revealed that the thinner walled piles produce higher degree of soil plugging at greater penetration depths. The results also revealed that the soil plug height is dependent on sleeve length of up to 2D length and independent beyond a 2D length. The piles of a smaller sleeve length (e.g., ≥ 1D) produce higher degree of soil plugging at shallow penetration depths while the piles of a larger sleeve length (e.g., ≦ 2D) produce higher degree of soil plugging at greater penetration depths.

Behaviour and Design of Connections for Demountable Steel and Composite Structures

This paper provides an overview of demountable connections and elements for steel and composite structures. Demountable connections are generally assembled from prefabricated structural members which can be reused after dismantling. This paper investigates innovative connections which enable steel and concrete framed structures to be made demountable. Demountable connections considered in this paper include beam-beam connections, column-column connections and beam-slab connectors. The finite element models for the nonlinear inelastic analysis of coped beams, column-column connections and composite beams are developed based on nonlinear finite element analysis techniques using the commercial finite element program, ABAQUS. The behaviours for coped steel beams and composite beams are then compared with the corresponding experimental results. The finite element models are used to investigate the effects of material and geometric properties on the behaviour of demountable connections. The finite element models can efficiently predict the plastic damage in the coped steel beam used in beam-beam connections. It is demonstrated that the coped beam can be made demountable up to a load of about 50% of the ultimate load which is greater than typical service loads. The computational results indicate that increasing the sleeve length and reinforcement ratio increases the stiffness and ultimate tensile strength of demountable column-column connections.

태권도복 착용 현황 및 디자인 선호에 관한 연구 -일반 소비자와 태권도 선수를 대상으로-

Abstract Currently, a lot of people are aware of their health and well-being, so they are concerned about their healthcare. ‘Taekwondo’ is one of the popular sports that Korean people are passionate about Taekwondo has also become globalized. The uniform of Taekwondo is gaining importance. Taekwondo involves a lot of movement, hence the pattern should facilitate the movement. In addition Taekwondo uniform pattern should meet the demands of functionality, fit and consumer design preferences. This study aimed to provide the basic data for development of Taekwondo uniform pattern based on design preferences and functionality to wearer satisfaction. The result of this method indicated fit and design details. Also, the length of pants, top, and sleeve was too wide, which has to more fitted for both of genders. For females, the breakpoint was too low, which requires some increase to make females feel more secure. In conclusion, the results of this study indicated that in order to increase ‘Takwondo’ value, Taekwondo uniform is required to be more fashionable and comfortable to wear, which could influence other sports wear.Keywords : Taekwondo Uniform( ), wear situation( ), design preference(태권도복 착용현황 디자인 ), functionality of movement( )선호도 동작기능성

Learning to Appreciate the Aesthetic Effects of Clothing

How do people describe clothing? The words like “formal”or "casual" are usually used. However, recent works often focus on recognizing or extracting visual features (e.g., sleeve length, color distribution and clothing pattern) from clothing images accurately. How can we bridge the gap between the visual features and the aesthetic words? In this paper, we formulate this task to a novel three-level framework: visual features(VF) - image-scale space (ISS) - aesthetic words space(AWS). Leveraging the art-field image-scale space served as an intermediate layer, we first propose a Stacked Denoising Autoencoder Guided by CorrelativeLabels (SDAE-GCL) to map the visual features to the image-scale space; and then according to the semantic distances computed byWordNet::Similarity, we map the most often used aesthetic words in online clothing shops to the image-scale space too. Employing upper body menswear images downloaded from several global online clothing shops as experimental data, the results indicate that the proposed three-level framework can help to capture the subtle relationship between visual features and aesthetic words better compared to several baselines. To demonstrate that our three-level framework and its implementation methods are universally applicable, we finally present some interesting analyses on the fashion trend of menswear in the last 10 years.

Design of planar monopole antenna in velvet shape having two gap sleeves

In this study, a wideband antenna was proposed by adding two strip sleeves with gaps according to a velvet shape in a planar monopole shape basically having the velvet structure. By adding two gap sleeves, additional resonance could be induced, thereby inducing impendence matching effectively. Through the antenna property analysis, it was confirmed that changes in the feed gap, sleeve length, and sleeve gap are important parameters of impedance matching. The total size of antenna substrate was 40 mm × 40 mm2, and FR4 dielectric substrate with 1 mm thickness was used. As a measurement result, the bandwidth of 10 dB was confirmed to be 12.09 GHz in the 2.91–15 GHz bands. In all frequencies, results similar to the radiation pattern of dipole antenna were shown. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:21–24, 2016

A cross-sectional observational study about media and infection control practices: are photographic portrayals of healthcare workers setting a bad example?

BackgroundAttempts to increase compliance with infection control practices are complex and are - in part - based on attempts to change behaviour. In particular, the behaviour of significant peers (role models) has been shown to be a strong motivator. While role models within the working environment are obviously the most important, some experts suggest that media and public display cannot be ignored. The aim of this present study was to examine the display of technique recommended by current infection control guidelines including the “bare below the elbow” principle, which is considered a basic requirement for good infection control in many countries, in sets of professional stock photos.FindingsFrom 20 random photo-stock websites we selected pictures with search terms “doctor and patient” and “nurse and patient”. In all selected photos a doctor or nurse and a patient were presented, healthcare workers (HCWs) were wearing white coats or uniforms, and their arms were visible. Each photo was evaluated with regard to: closure of white coat, sleeve length, personal clothing covered, hairstyle and presence of a wristwatch, bracelet and/or ring. Overall, 1600 photos were evaluated.The most common mistakes were with regard to HCWs’ white coats/uniforms. Eighty-nine percent of the photos containing doctor’s images were considered incorrect while 28 % of nurse-containing photos were incorrect.ConclusionsThe results seem to reflect the real world with only 40 % displaying correct behaviour with doctors being worse than nurses. It seems that the stereotypical image of a doctor does not agree with the current infection control guidelines. If we aim for higher compliance rates of HCWs, we need to change the social image of doctors and improve production, selection and display of stock photo images.

Optimization of Shaft Sleeve Slippage in High-Voltage Circuit Breaker Operation Mechanism

High-voltage circuit breakers are mechanical switching devices which connect and break current circuits (operating currents and fault currents) and carry the nominal current in closed position. As a result of multi-running, the shaft sleeve in operation mechanism could slip and even strip from the shaft at the hinge joint, which decreases the system reliability. In this work, investigations on the cause of sleeve slippage are proceeded, and the dimension parameters of shafting components where sleeve slippage occurs are optimized by incorporating a quasi-static mechanical model with Taguchi method. By developing and analyzing the mechanical model for the shaft sleeve slippage, it indicates that the sleeve slippage displacement has a same variation tendency with the shaft deflection. Theoretical equations are derived by using force analysis and superposition method to descript the analytic function of the shaft deflection. As the variables within the analytic function of the shaft deflection, the diameter and length of the shaft and the corresponding shaft sleeve length are selected as the control parameters in the optimization model. Moreover, several experiments are conducted by using the L18 (mixed orthogonal array) design method. Considering that the local mechanical characteristics such as sleeve strain are difficult to monitor via experimental method, an FEM simulation model is established to give the sleeve slippage displacement. Different levels of control parameters are introduced into the mechanical model and FEM simulation according to Taguchi method. The results from signal-to-noise (S/N) and ANOVA analysis (analysis of variance) reveal that shaft diameter is the most significant factor determining sleeve slippage in high-voltage circuit breaker operation mechanism, and that a larger diameter of shaft, a shorter shaft length and a longer sleeve length can reduce the sleeve slippage effectively. Meanwhile, the theoretical model is verified and enhanced by the FEM model.

비주얼 의류 검색기술을 위한 의류 속성 기반 Annotation 기법 개발

Mobile (smartphone) search engine marketing is increasingly important. Accordingly, the development of visual apparel search technology to obtain easier and faster access to visual information in the apparel field is urgently needed. This study helps establish a proper classifying system for an apparel search after an analysis of search techniques for apparel search applications and existing domestic and overseas apparel sites. An annotation technique is developed in accordance with visual attributes and apparel categories based on collected data obtained by web crawling and apparel images collecting. The categorical composition of apparel is divided into wearing, image and style. The web evaluation site traces the correlations of the apparel category and apparel factors as dependent upon visual attributes. An appraisal team of 10 individuals evaluated 2860 pieces of merchandise images. Data analysis consisted of correlations between apparel, sleeve length and apparel category (based on an average analysis), and correlation between fastener and apparel category (based on an average analysis). The study results can be considered as an epoch-making mobile apparel search system that can contribute to enhancing consumer convenience since it enables an effective search of type, price, distributor, and apparel image by a mobile photographing of the wearing state.