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The goal of this research article is to investigate the effects of using two-dimensional functionally graded materials on the performance of piezoelectric sensors/actuators when subjected to simultaneous complex loading conditions. The considered disc-shaped sensors/actuators have nonuniform thicknesses and undergo asymmetric hygro-thermo-electro-mechanical loading. A power-law model is used to grade the materials radially, whereas the cosine function, which includes two independent parameters, describes the pattern along the circumferential direction. Comparing the results obtained by using the finite element method with those of one-dimensional graded structures leads to promising outcomes. For example, the radial displacement exhibits vital changes that varied between - 13 and 31 % . This is beneficial for such structures in terms of enhancing their sensing/actuating abilities. Also, the tangential stress can be reduced substantially by about 39.5 % through the proper selection of the corresponding material parameters. In addition, this reduction of the tangential stress has a positive effect on the von Mises stress that can be decreased by nearly 33 % . Accordingly, the structure would have improved durability and sustain higher loads. These findings would revolutionize the manufacturing of smart structures and enhance their behaviors under severe conditions. [ABSTRACT FROM AUTHOR]

The aim of the work is to develop a physical and mathematical model of the process under complex asymmetric loading in conditions of single-area and two-area deformation zone during plastic processing of medium-thickness strips. The stress state in case of loss of stability during rolling of strips of medium thickness was investigated. The patterns of changes in the stress state of the strip under conditions of reach of the limiting deformation zone, as well as the effects of plastic shaping determined by a decrease in contact stresses under conditions of increasing deformation loading, are revealed. The described method is a visual approach to assessing the stress state of a plastic medium under conditions of complex interaction and asymmetric loading. [ABSTRACT FROM AUTHOR]

Quantitative determination of the critical size of an inclined coal pillar in an old goaf water-affected area is of great significance for water damage prevention and safe mining. The critical size of the inclined waterproof coal pillar is derived by using mechanical analyses, numerical calculations, and field engineering practices to determine the stability of the waterproof coal pillar in the old goaf water-affected area of the 1303 working face of Dananhu No. 1 Mine in the Xinjiang region. Firstly, a force model of the inclined waterproof coal pillar was established to reveal the law that the critical size of the coal pillar increases with the increase in coal seam inclination under the action of asymmetric load. Then, numerical simulation was applied to reveal the dynamic evolution processes of plastic deformation–destabilization of the coal pillar under the influence of mining and single-side water pressure, and the critical size of the coal pillar in the study area was determined to be 19.09 m. Finally, measures such as pumping pressure relief and slurry reinforcement were adopted to reduce the deformation rate of the roadway on the side of the coal pillar, which ensured the stability of the waterproof coal pillar and the safe mining of the working face. [ABSTRACT FROM AUTHOR]

The objective of this study is to examine through the finite element method the impacts of employing two-dimensional (2D) properties grading on the behaviors of piezoelectric sensors/actuators due to their significance. These structures are modeled as variable thickness discs and are assumed to be exposed to simultaneous asymmetric loading conditions (thermal, hygral, electrical, and mechanical loads). Results demonstrate that the 2D grading is superior compared to the conventional one-dimensional grading for reducing the von Mises stress. The reduction reached, for instance, 8.3% allowing further increase of loading and/or safety. Also, the change of the displacement is varied between −4.5% and 31% depending on the considered grading pattern, and thus can be controlled to a desired value which helps to improve the sensing and actuating functionality for certain requirements. The study also examines the effects of porosity, and the results are compared to nonporous discs. Reductions of the maximum compressive tangential stress and von Mises stress reached 79.75% and 33.6%, respectively at specific porosity distribution patterns and volume fractions. These findings have significant implications for the manufacturing of smart structures, enabling them to operate in severe working conditions with better sensing and actuating capabilities than previously possible. [ABSTRACT FROM AUTHOR]

This study presents a 2D comprehensive analytical and numerical analysis of the thermomechanical stresses in an unsymmetric dual compound thick cylinder under steady-state conditions. By employing mathematical analysis, this research aims to investigate the effectiveness of a 2D compound cylinder in reducing elastic and thermoelastic stresses. The temperature and displacement fields are thought to be dependent on the radial and circumferential directions, subject to asymmetric thermal and mechanical boundary conditions on the inner and outer surfaces. In this scenario, the Poisson ratio is considered to be a constant. The techniques of variable separation and complex Fourier series are employed analytically in the solution of heat conduction and Navier equations. The results obtained from the developed analytical method are compared and validated against those obtained from a finite difference method (FDM). The findings of this study suggest that the clamping of the outer layer has a significant influence on stress distribution in the structure, and the impact of tangential stress on the behavior of a compound cylinder is highly dominant. Furthermore, changes in temperature significantly influence hoop stress compared to variations in internal pressure levels. Moreover, the influence of internal pressure is relatively attenuated when a pressure vessel is fabricated utilizing different metals. In addition, the findings indicated that the configuration of layers and the location of the highest temperature had a significant impact on the performance of the vessel. Nevertheless, the technology provided has sufficient robustness to effectively address the complexities associated with the design of multilayered graded materials (GM) in additive manufacturing applications.

This article discusses the construction of a nodal bridge on Shanghai Rail Transit Line 10 above Line 6. Based on the analysis of the advantages and disadvantages of various construction methods, a new type of asymmetric loading cantilever assembly method with a bridge erecting machine is proposed. Firstly, the east half of the bridge is constructed to form a T-shaped structure, and then the bridge erecting machine uses the built T-shaped structure to provide a fulcrum to pass the holes and complete the construction of the west half of the bridge. The two parts are then closed. The method proposed in this paper can solve construction issues when working space under a bridge is limited, and the conventional balanced cantilever assembly method cannot be used for construction. [ABSTRACT FROM AUTHOR]

Accurately simulating the nonlinear response of reinforced concrete (RC) columns under cyclic loading is crucial in performance-based seismic design for building structures, especially regarding strength degradation. This paper presents the description, calibration and simulation of the hysteretic model for RC columns based on effective hysteretic energy dissipation with positive and negative directions. During the analysis of previous experimental data, the relationship between hysteresis energy dissipation, maximum displacement, and the effects of positive and negative loading directions on strength degradation has been summarized. The proposed method for determining the yield strength of the hysteresis loop is based on the farthest point method. Calibration of the hysteretic models' existing RC columns' experimental data demonstrates that the proposed model can simulate the main characteristics that influence deterioration. [ABSTRACT FROM AUTHOR]

The goal of this research study is to examine, through the finite element method, the efficiency of using two-dimensional (2D) functionally graded materials (FGMs) in lowering the elastic/thermoelastic stresses acting on cylinders. In 2D-FGMs, the properties are assumed to vary in the radial and tangential directions simultaneously, which is rarely investigated in the literature. The cylinder is subjected to asymmetric inner normal traction with/without asymmetric thermal loading. For the considered case studies, results revealed that 2D-FGMs is beneficial compared to the conventional grading. In case of considering mechanical load only, the tangential stress declines by almost 39%. Similarly, accounting for thermomechanical load resulted in radical falls for the tangential and axial stresses by around 63% and 61%, respectively. Accordingly, the von Mises stress declines dramatically with different values allowing for safe load escalation, and enhancing the cylinder's durability. Finally, no certain values for the used tangential function's parameters are preferred to have maximum reduction of stresses under all working circumstances, which necessitates performing optimization. [ABSTRACT FROM AUTHOR]

Copyright of Przegląd Elektrotechniczny is the property of Przeglad Elektrotechniczny and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this article, a periodic leaky‐wave antenna (LWA) with wide‐angle beam scanning and stable gain is proposed based on the meandering microstrip line. Due to the meandering property of the microstrip line, the longitudinal dimension of the antenna is reduced. Firstly, the radiation characteristic of the meandering microstrip line is analyzed in detail. Each corner of the meandering microstrip line is modeled by a shunt capacitance and shunt radiation conductance to acquire the equivalent circuit. Then, the frequency balanced condition is investigated based on the established equivalent circuit to realize continuous beam scanning through broadside. Subsequently, the method of open‐stop band (OSB) suppression is studied by introducing asymmetric perturbation on the LWA unit cell, which actually can be applied to eliminate the OSB effect in arbitrary symmetric LWAs. Finally, an antenna prototype is simulated and measured. The measured results agree well with the simulated results, validating the proposed method of OSB suppression. The measured results show that the designed antenna exhibits the beam scanning capacity of −47° to +76° with the frequency varying from 5.0 to 7.8 GHz and gain variation of 2.9 dB. [ABSTRACT FROM AUTHOR]

Accurately simulating the nonlinear response of reinforced concrete (RC) columns under cyclic loading is crucial in performance-based seismic design for building structures, especially regarding strength degradation. This paper presents the description, calibration and simulation of the hysteretic model for RC columns based on effective hysteretic energy dissipation with positive and negative directions. During the analysis of previous experimental data, the relationship between hysteresis energy dissipation, maximum displacement, and the effects of positive and negative loading directions on strength degradation has been summarized. The proposed method for determining the yield strength of the hysteresis loop is based on the farthest point method. Calibration of the hysteretic models’ existing RC columns’ experimental data demonstrates that the proposed model can simulate the main characteristics that influence deterioration.

This article introduces a novel mixed method that combines the Fast Fourier Transform technique and a conventional Finite Element Method for investigating thermo-mechanical behavior of a thick functionally graded cylinder under asymmetric loadings. Material properties are assumed to vary along the radial direction according to a power function. Thermo-elastic governing equations of the cylinder are derived using principle of virtual work in cylindrical coordinates. Plane strain assumption is considered for a long cylinder during the analysis. Fast Fourier Transform technique is utilized in circumferential direction to discretize equations and related boundary conditions. Finite element method is then applied to remaining equations. For convergence study, the results obtained from this method are compared with those extracted from exact and complete FE solutions. It is observed from the results that the method has a super algebraic convergence behavior in circumferential direction. Influence of the mesh refinement is also investigated in the radial direction. According to ability of the mixed FFT-FE method for asymmetric analyzing, two kinds of loadings are considered here and results are presented. In thermoelastic analyzing of the long cylinder, it's obvious that the present method benefits from some features such as fast convergence and low computational cost in comparison with FE solution. [ABSTRACT FROM AUTHOR]

The performance of cross-laminated timber (CLT) panels in building applications have been investigated extensively. However, limited information is available regarding the performance of CLT panels for bridge applications, as well as the torsional performance of CLT panels under asymmetric loading, geometry, and boundary conditions. The objective of this study was to investigate the torsional performance of skewed CLT pedestrian interior bridge deck panels through large-scale structural testing. The panels were designed as a pedestrian bridge crossing over an atrium of The Canyons building in Portland, OR. The test panels were subjected to line and uniformly distributed loads to replicate the reactions from the adjacent panels and design loads directly applied to the panel, respectively. Two different loading configurations based on the 2014 Oregon Structural Specialty Code (OSSC) were applied with up to three different loading intensity levels. An additional loading configuration, which was beyond the scope of the OSSC, was also applied in the second series of tests to determine if panel failure could be induced. The test results demonstrated that the test panels were able to recover their original shape without suffering major damages on the panel. The measured residual deformation after the removal of the applied load was very small. The findings of this study broaden the current state of knowledge of the structural performance of a CLT bridge deck panel under asymmetric loading, and the test results can be used for future design problems. [ABSTRACT FROM AUTHOR]

This paper aims to develop semi-analytical results of the poromechanical fields in a hollow cylinder subjected to an asymmetric loading condition. The poroelastic properties of the hollow cylinder vary in the radial direction. The heterogeneous hollow cylinder is approximated by a multilayer structure in which each cylindrical layer is assumed to be homogeneous. The analytical results of the poromechanical field are first established in the transformed Laplace space, and then the ones in time space are obtained by the inverse Laplace transformation. They are perfectly in coherence with existent results in the literature that were developed for the homogeneous and the heterogeneous cases at the steady state regime. Sensitivity analysis shows a significant effect of the radial variations of the poroelastic properties on the response of the hollow cylinder. [ABSTRACT FROM AUTHOR]

The monopile is the most common form of foundation employed in offshore wind turbines. These foundations are subjected to millions of repeated load cycles, owing to wind and wave action. In this study, a series of six cyclic lateral load tests and two monotonic tests were performed on an aluminum model pipe pile with an outer diameter of 63.5 mm and a wall thickness of 2.5 mm. A model monopile was embedded in medium dense sand (Dr = 55%) and subjected to asymmetric two-way cyclic loading. From the experimental investigations, the effects of embedded length and the asymmetric two-way cyclic loads on the lateral pile head displacements and the cyclic secant stiffness of the soil–pile system were studied. Linear regression analysis was also performed to fit the conventional degradation parameters using the minimum number of critical constraints, which included the loading conditions and the flexibility parameters of the soil–pile system. From the test results, it was observed that asymmetric two-way loading causes a reversal of accumulated displacement for a pile embedded at a greater depth (L > 1.91T) under relatively lower amplitudes (ζb < 0.37). The cyclic secant stiffness was observed to increase at a relatively constant rate (Aκ) with the logarithm of the number of cycles. The study also revealed that the magnitude of initial cyclic secant stiffness, in comparison with the monotonic stiffness, exhibited a critical drop near the specific load character, ζc = −0.38. [ABSTRACT FROM AUTHOR]

Objective: To measure age‐related changes in thoracic vertebral body heights (VBH) in skeletally immature normative and scoliotic rabbits to assess how VBH change during growth. To examine the potential link between the moment‐arm of the rib tether and vertebral wedging as well as the sum of the curvature angles at the apical level (T7). To assess the correlation between the magnitude of initial spine curve and final spine curve in the scoliotic group. Methods: Eight healthy, skeletally immature normative New Zealand rabbits and ten skeletally immature scoliotic rabbits which underwent unilateral rib tethering were included retrospectively. Each rabbit was scanned at two to four time points (at 7, 11, 14 and 28 weeks). Three dimensional bone models of thoracic vertebrae (T1‐T12) were digitally segmented and reconstructed. VBH were calculated using surface landmark points from each thoracic vertebra. Apical level (T7) ± 2 levels in scoliotic rabbits were compared to their corresponding levels and time points in the normative group. The moment‐arms between the centroids of 2D projections of T3‐T9 vertebral bodies and the line which connects the centroids of the end levels were calculated. Results: Bilateral left‐right (L‐R) symmetry and anterior‐posterior (A‐P) asymmetry were observed in normative VBH. Bilateral concave‐convex (CC‐CX) asymmetry and (A‐P) asymmetry were observed in scoliotic VBH. No significant differences in growth rates were found between the normative and scoliotic groups. Vertebral wedging as well as curvature magnitude were positively correlated with the moment‐arms. Conclusion: Unilateral rib tether applies compressive forces on both concave and convex sides, whereas compressive forces are lower on the latter. Knowing the amount of vertebral wedging or curve magnitude would enable us to predict the applied force (moment‐arms), which is important for planning a corrective surgery. [ABSTRACT FROM AUTHOR]

This paper presents results of tests on 18 one-way reinforced concrete slabs under point loads having as main variable the transverse flexural reinforcement ratio, the loading position and the width of the slab. The response of the slabs is described and discussed in terms of deflections, strains of the concrete and of rebars, cracking pattern, failure modes and failure loads. Experimental results are also used to discuss and evaluate theoretical treatments presented by American Concrete Institute 318 (ACI, 2014) and Eurocode 2 (Comité Européen de Normalisation [CEN], 2005). All slabs failed by punching shear and results indicate that the recommendations presented by the codes are conservative, especially those related to the prediction of one-way shear resistance of reinforced concrete flat slabs.

A continuous contact problem of functionally graded layer resting on an elastic semi-infinite plane, which is loaded with through two different blocks is addressed in this study. The elasticity theory and integral transformation techniques are used in solution of the problem. The problem is reduced to a system of singular integral equations, and solved numerically by the aid of appropriate Gauss-Chebyshev integration formula. It is assumed that the elastic semi-infinite homogeneous plane is isotropic and all surfaces are frictionless and continuous. The shear modulus and the mass density of the FG layer vary exponentially along the thickness direction. [ABSTRACT FROM AUTHOR]

Abstract: The current study has attempted to comprehensively review ratcheting response of materials involving various influential parameters such as loading spectra, thermal cycles, stress levels, stress raisers, strain rate, and visco‐plasticity and material types with a focus on pressurized pipes and equipment. The mechanism of deformation, types, and the rate of progress over stages of ratcheting were discussed. Safety design codes and procedures were highlighted for reliable design of pressurized pipes against progressive ratcheting and to safeguard the system against catastrophic failure at which both mechanical and thermal ratcheting were integrated. Boundaries and demarcation of ratcheting‐shakedown zones developed based on Bree's diagram were employed to assess plastic deformation accumulation over stress cycles. Shakedown and ratcheting boundaries were discussed through methods developed on the basis of Melan's theorem over last few decades. Ratcheting response of materials was reviewed through descriptions of parametric models and kinematic hardening rules involving various variables and parameters. Interaction of ratcheting with creep and low‐cycle fatigue has promoted progressive damage in materials. Pressurized pipes subjected to thermal cycles and external bending cycles were evaluated by numerical solutions along with kinematic hardening rules to assess ratcheting over stress cycles. [ABSTRACT FROM AUTHOR]

The paper considers a limit state and fatigue life calculation problem of prismatic bars under the joint action of symmetric cyclic bending and static torsion. The solution is constructed using the equivalent stress method. A cyclic stress under symmetric cycle conditions was chosen as an equivalent stress. The results of the calculation have been evaluated experimentally for alloyed steels and an aluminum alloy as an example. [ABSTRACT FROM AUTHOR]

The article deals with two spans steel split-type one band pedestrian suspension bridge structure. Structural behaviour of such suspension member subjected to asymmetrical load has been discussed under the condition of temporary load influence imposed on one span out of two. Two structural solutions of one band suspension bridges have been considered: with completely flexible retaining elements, and in case of bending rigid. The article provides analytical expressions for calculations of the displacements of these asymmetrically loaded suspended elements, thrust forces and bending moments. Simplified analytical method accuracy of one band bridges is illustrated on the basis of performed numerical experiment Performed numerical experiment shows the resulting basis of simplified analytical method accuracy of one band bridges.

A piled wharf is a type of foundation suitable for thick soft soils, but the elastic-plastic deformation and creep of the soft soil may affect the structural safety. The asymmetric damage to the beams on the rear piled platform of a piled wharf in Tianjin Port was analyzed according to the results of structural testing and deformation observation, it was concluded that the asymmetrical loading and creep of soil mass had caused the damage. In this paper, the deformation and damage of the piled wharf under asymmetric loads was calculated and analyzed by the Singh-Mitchell Model to simulate the creep of soil and the 3D finite element method. The calculation results show that the structural deformation and damage to the piled wharf is consistent with the results of structure testing. The numerical analysis method in the paper may well reflect the structural deformation and damage to a piled wharf under the asymmetric loading and with the creep of soil, which provides scientific basis to ensure the structural safety of piled wharfs. [ABSTRACT FROM AUTHOR]

Idiopathic scoliosis is a deformity of the spinal column and is found among healthy children. Etiology of idiopathic scoliosis is unknown. Spinal shift occurs in all three planes followedby muscle disfunction and reduced vital capacity of the lungs. Asymmetric loading on the spinecan be listed as one of the factors of rapid progression of scoliosis, whereby large pressure is put onthe concave side of the scoliotic curvature due to the shift of standing balance of the body. Rehabilitation is based upon improvement of functionality, ability and capacity of the patient with scoliosis. The initial stage of rehabilitation rests on correct diagnosis and estimation of patient’s condition in order to commence the treatment in the best possible manner. The Schroth method has along-standing tradition and is primarily applied in correction of scoliosis. It is based on three-dimensional breathing, proper pelvic correction and specific exercises and education of patients inorder to continue the treatment at home.

Copyright of Acta Scientiarum: Technology is the property of Universidade Estadual de Maringa and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Mechanical Engineering the National Technical University of Ukraine 'Kyiv Polytechnic Institute' is the property of National Technical University of Ukraine KPI and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Based on the first-order nonlinear von Karman theory, the post-buckling analysis of FG circular plates under asymmetric transverse and in-plane loadings are presented. The nonlinear governing equations are reformulated using a stress function and a boundary layer function, and solved by employing a multi-parameter perturbation technique and Fourier series method. The material properties are assumed to vary through the plate thickness according to a power-law distribution of the volume fractions of the constituents. The results are verified with the known results in the literature. The effects of loading, material properties, and boundary conditions on different response quantities are studied. It is observed that the buckling load in clamped FG plates under asymmetric in-plane loading is lower than that of the same plate under axisymmetric in-plane loading. It is concluded that under downward transverse loading, the snap buckling occurs in simply-supported FG plates with an initial considerable upward deflection caused by an in-plane load. In addition, the behavior of boundary layer in FG plates under in-plane loading is studied and compared with that in transverse loading. [ABSTRACT FROM AUTHOR]

BACKGROUND: Carrying a backpack is common among schoolchildren. The effect of backpack load on spine pain and posture defects in children is often raised in the literature. According to scientific research, the maximum backpack load that is safe for children must not exceed 10-15% of their body mass. There is a lack of scientific reports related to the effect of frequently wearing a backpack on one shoulder among children and young adults and its influence on the shape of the anterior-posterior curvatures of spine. OBJECTIVES: The aim of this study is to evaluate body posture parameters in the sagittal plane for an asymmetrical backpack load equal to 10% of a child's body mass. METHODS: The study was conducted using 162 primary schoolchildren aged 11-13 years. Each participant underwent three tests that examined postural parameters, including habitual posture, with the backpack on the participant's right and left shoulder. Posture was measured with the CQ Elektronik; which uses photogrammetry to make anthropometric calculations based on an image of the examined surface. RESULTS: The asymmetrical backpack load resulted in a significant reduction of thoracic kyphosis (GKP: p - 0.040). The angle of thoracic kyphosis increased between the measurements. The difference (GAMMA = 0.054) revealed that the results were approaching significance. CONCLUSIONS: Considering the gravity of the problem, children should be educated on ergonomics by teachers, physiotherapist or nurses, including instructions on carrying a backpack and the effects of disregarding the basic rules on body posture, as part of their school curriculum. The acceptable backpack load, which is now believed to be 10% of the child's body mass, should be carefully considered by scientists. Our own results show that even a load of 10% of the body mass may induce negative changes in spinal posture. [ABSTRACT FROM AUTHOR]

The dependence of the shape of flexible shafts on the force application in asymmetric hardening by surface plastic deformation is experimentally studied. [ABSTRACT FROM AUTHOR]

Creation of engineering structures is closely related to the need of improving the methods for strength calculation. This task is especially relevant with regard to the parts subject to cyclic loadings, causing premature failure as a result of the development of the metal fatigue process. In this regard, it is important to develop the research aimed at finding adequate model approximations that describe the interrelation of durability of a construction material with the range of loading conditions and the number of structural features of parts made of it. The method of calculating the safety margin of parts of engineering structures subject to the combined effects of static and cyclic loadings is considered in this paper. The focus is on assessing the maximum limit stresses characteristic of the asymmetric loading of structural materials, taking into account the stress concentration as one of the main factors inherent in real structural elements. The proposed approach provides more correct calculation of the margin of safety in the implementation of design works. Thus, the research results given in this paper are of both scientific and practical interest. The authors proposed a method for assessing the margin of safety of constructional materials subject to asymmetric cyclic loading, based on the previously developed models of the limit state based on the use of power transcendental functions. [ABSTRACT FROM AUTHOR]

Cable structures are very efficient (in economic aspect) when applied to cover large spans. The cable structure consists of a single cable or a network of cables. The cable attractive feature is the highest ratio of strength to weight amongst other carrying structural elements, usually applied in engineering practice. But a cable is a specific structural element able to response only one type of deforming †tension (flexural rigidity actually vanishes). Therefore, when loaded a cable shapes the form to resist tension only. This adaptation is followed by large nonlinear displacements. Thus, the nature of geometrical nonlinear cable behavior is quitie a different from that of rigid structural elements. Both elements response via small deformations when loaded, but large displacements of a cable are conditioned by its adaptation to loading, and those of rigid structural elements †by actual deformations. One can also note that deformations of a cable are significantly less than those of rigid structural elements, but at the same time actual cable displacements are significantly larger. Thus, the main disadvantage of a cable structure is its response to loading by large displacements caused by asymmetric loading component (usually met in engineering practice, e.g. the design of suspension bridges, coverings of stadium, etc). Therefore stiffness conditions predominate in the actual codified cable design. Having identified governing factors conditioning displacement magnitudes one can introduce the constructional means/solutions assigned to reduce them if required. Therefore the evaluation of cable displacements by a reliable and sufficiently exact method compatible with the calculation of actual engineering structures is under current necessity. When analyzing total displacements the principle of superposition is employed in a special sequence. Total displacement is split into two components: kinematic and elastic. The first component represents cable form shaping the loading, the second one is conditioned by elastic deformations. Any point displacement of an asymmetrically loaded cable can be expressed via its middle span. The developed analytical expressions to evaluate middle span displacements are presented. They enable to identify maximal displacements and their locations. The developed analytical method for total displacements evaluation is tested numerically. The comparative analysis in respect of the influence of various parameters conditioning displacement magnitudes is performed. The displacement evaluation errors, their causality conditioned by the application of approximate†widely applied engineering methods, are discussed. Apkrauto lyno apybraižos nustatymas per pilnuosius poslinkius Santrauka Kabamosios konstrukcijos yra labai efektyvios (ekonominiu atžvilgiu), kai naudojamos dideliems tarpatramiams perdengti. Jos gali bÅ«ti sudarytos iÅ¡ atskirų kabamųjų lynų arba jų sistemų. Palyginti su įprastiniais laikanÄiųjų konstrukcijų elementais, kabamojo lyno patrauklumÄ… atskleidžia mažiausias santykis tarp jo laikomosios galios ir savojo svorio. SpecifinÄ— lyno savybÄ— ta, kad jis gali dirbti tik tempimui (jis praktiÅ¡kai neturi standumo lenkimui). TodÄ—l lynas, veikiamas nepusiausvirosios apkrovos, keiÄia savo pradinÄ™ apybrėžą, kad prisitaikytų prie jos, sukelianÄios tik tempimo įrąžą. Å is prisitaikymas lemia didelius netiesinius poslinkius. Taigi lyno geometriÅ¡kai netiesinÄ—s elgsenos pobÅ«dis skiriasi nuo standžių konstrukcijų netiesinÄ—s elgsenos. Nors abiejų tipų elementuose pasireiÅ¡kia nedidelÄ—s deformacijos, dideli lyno poslinkiai yra sukeliami adaptacinio formos pasikeitimo, o standžiuosiuose elementuose didelius poslinkius sukelia tik deformacijos. Reikia pabrėžti, kad lyno tampriosios deformacijos paprastai yra mažesnÄ—s už analogiÅ¡kas standžiuosiuose elementuose, bet lyno poslinkiai yra gerokai didesni. Taigi esminis apkrauto lyno elgsenos trÅ«kumas yra dideli poslinkiai, kuriuos lemia asimetrinÄ—s apkrovos (bÅ«dingos tokioms konstrukcijoms, kaip kabamieji tiltai, stadionų stogų perdangos ir t. t.). TodÄ—l projektuojant kabamÄ…sias konstrukcijas svarbiausios yra standumo sÄ…lygos. Gana tikslaus ir patikimo metodo sukÅ«rimas realių kabamųjų konstrukcijų poslinkiams nustatyti yra neabejotinai aktualus. Nustatant pilnuosius (suminius) poslinkius, sumavimo principas realizuojamas tam tikra seka. Poslinkiai skaidomi į du komponentus: kinematinį ir tamprųjį. Pirmasis atsiranda dÄ—l lyno formos pasikeitimo, jam adaptuojantis prie asimetrinÄ—s apkrovos pobÅ«džio, antrasis †dÄ—l tampriųjų deformacijų. Kiekvienas simetriÅ¡kai apkrauto lyno poslinkis gali bÅ«ti iÅ¡reikÅ¡tas naudojant vidurinį lyno poslinkį. Pateiktos patobulintos analitinÄ—s iÅ¡raiÅ¡kos viduriniam lyno poslinkiui nustatyti. Jos leidžia nustatyti didžiausius lyno poslinkius ir jų vietas. Pateiktos iÅ¡raiÅ¡kos suminiams poslinkiams nustatyti yra patikrintos skaitiÅ¡kai, atlikta lyginamoji analizÄ— siekiant įvertinti atskirų parametrų, nusakanÄių poslinkio didumÄ…, indÄ—lį. Aptartos poslinkių nustatymo paklaidos ir jų priežastys, gaunamos plaÄiai taikant apytikslius inžinerinius metodus. ReikÅ¡miniai žodžiai: kabamojo lyno apybraiža, netiesinÄ— analizÄ—, asimetrinÄ— apkrova, pilnieji poslinkiai. First Published Online: 21 Oct 2010

This paper presents a method and procedure of sensing and determining critical shear buckling load and corresponding deformations of a comparably large composite I-section using strain rosettes and displacement sensors. The tested specimen was a pultruded composite beam made of vinyl ester resin, E-glass and carbon fibers. Various coupon tests were performed before the shear buckling test to obtain fundamental material properties of the I-section. In order to sensitively detect shear buckling of the tested I-section, twenty strain rosettes and eight displacement sensors were applied and attached on the web and flange surfaces. An asymmetric four-point bending loading scheme was utilized for the test. The loading scheme resulted a high shear and almost zero moment condition at the center of the web panel. The web shear buckling load was determined after analyzing the obtained test data from strain rosettes and displacement sensors. Finite element analysis was also performed to verify the experimental results and to support the discussed experimental approach. [ABSTRACT FROM AUTHOR]

Abstract: The equilibrium equations of the first-order nonlinear von Karman theory for FG circular plates under asymmetric transverse loading and heat conduction through the plate thickness are reformulated into those describing the interior and edge-zone problems of the plate. A two parameter perturbation technique, in conjunction with Fourier series method is used to obtain analytical solutions for nonlinear behavior of functionally graded circular plates with various clamped and simply-supported boundary conditions. The material properties are graded through the plate thickness according to a power-law distribution of the volume fraction of the constituents. The results are verified with known results in the literature. The load–deflection curves for different loadings, boundary conditions, and material constant in a solid circular plate are studied and discussed. It is shown that the behavior of FG plates with clamped or simply-supported boundary conditions are completely different. Under thermo-mechanical loading, snap-through buckling behavior is observed in simply-supported FG plates which are immovable in radial direction. Moreover, it is found that linear theory is inadequate for analyzing FG and also homogenous plates with immovable boundary supports in radial direction and subjected to thermal loading, even for deflections that are normally considered small. [Copyright &y& Elsevier]

Abstract: Treated is the asymmetric static and dynamic response of a stack of layered thick disks from external load. Variables of the three-dimensional equations are separated assuming approximate simple supports along the cylindrical perimeter, yielding non-orthogonal eigenfunctions. This also couples the truncated set of radial wave numbers. Applying a radial transform to all variables eliminates radial dependence producing a diagonal eigenproblem in all coupled axial wave numbers. Comparing 3-D and 2-D asymmetric models of industrial glass disks reveals that the 3-D resonances are close to their 2-D counterparts adopting the Mindlin model. A Fourier analysis of a specific asymmetric line-load from pressure or thermal expansion produces a scale factor to static stress from a limited number of asymmetric solutions each with a different circumferential wave number. [Copyright &y& Elsevier]

Copyright of Baltic Journal of Road & Bridge Engineering (Baltic Journal of Road & Bridge Engineering) is the property of Baltic Journal of Road & Bridge Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract: A numerical model for resonant frequency using asymmetric loading is presented using cavity model. In asymmetric loaded antenna, the posts are not equispaced on annular ring antenna and resonant frequency is independent of the angular location of posts. The posts are located away from the centre of patch. The diameter of post is thin as compared to the diameter of annular ring antenna. The first few dominant modes calculated for asymmetric loading are compared to symmetric loading where the posts are to be located at specific angular locations. The theoretical model is compared to the simulated results of IE3D based on Method of Moments. The numerical model developed can also be verified further by the full wave analysis. [Copyright &y& Elsevier]

Abstract: Based on the first-order shear deformation plate theory with von Karman non-linearity, the non-linear axisymmetric and asymmetric behavior of functionally graded circular plates under transverse mechanical loading are investigated. Introducing a stress function and a potential function, the governing equations are uncoupled to form equations describing the interior and edge-zone problems of FG plates. This uncoupling is then used to conveniently present an analytical solution for the non-linear asymmetric deformation of an FG circular plate. A perturbation technique, in conjunction with Fourier series method to model the problem asymmetries, is used to obtain the solution for various clamped and simply supported boundary conditions. The material properties are graded through the plate thickness according to a power-law distribution of the volume fraction of the constituents. The results are verified by comparison with the existing results in the literature. The effects of non-linearity, material properties, boundary conditions, and boundary-layer phenomena on various response quantities in a solid circular plate are studied and discussed. It is found that linear analysis is inadequate for analysis of simply supported FG plates which are immovable in radial direction even in the small deflection range. Furthermore, the responses of FG materials under a positive load and a negative load of identical magnitude are not the same. It is observed that the boundary-layer width is approximately equal to the plate thickness with the boundary-layer effect in clamped FG plates being stronger than that in simply supported plates. [Copyright &y& Elsevier]

A deformed state of parabolic shape suspension cable subjected to asymmetric loading is under consideration. The cable kinematic nature of vertical and horizontal displacements, resulted from complementary asymmetrically distributed load are investigated, the expressions for their maximum values are derived. The deformability of suspension cable versus its curvature increment is investigated. The possibilities to stabilise the primary parabolic shape of suspension cable subjected to an asymmetric load are examined. Numerical simulation results are presented. First Published Online: 14 Oct 2010

Abstract: This experimental study examines the flow characteristics over a square cross-section body with sharp edges, a rectangular one with rounded edges, and a high wing-body configuration, in a low subsonic free stream. Pressure, velocity, force measurements and flow visualization provide a picture of the flow behaviour, locally and globally. Flow visualization and velocity measurements clearly depict the presence of two axial counter-rotating vortices in the leeside of the first two bodies, being mainly responsible for the asymmetric loading at nonzero roll angles, maximizing the side-force at a roll angle of about 25°. For all body orientations there is always a recirculation region at the nose-afterbody junction leeside area, the extent of which depends mainly on the roll angle. Pressure gradients take high values at the corners of the after body cross-section, even when these are rounded. No asymmetries were practically detected for a zero roll angle and pitch angles up to 20° for the examined three models. The wing-body configuration exhibits a higher lift slope and a more negative zero lift angle, compared to the wing-alone case, and the side-force increases monotonically with the roll angle, without showing any maximum in contrast to the other two models. [Copyright &y& Elsevier]

he contact problem for an elastic layer resting on an elastic half plane is considered according to the theory of elasticity with integral transformation technique. External loads P and Q are transmitted to the layer by means of two dissimilar rigid flat punches. Widths of punches are different and the thickness of the layer is h. All surfaces are frictionless and it is assumed that the layer is subjected to uniform vertical body force due to effect of gravity. The contact along the interface between elastic layer and half plane will be continuous, if the value of load factor, λ, is less than a critical value, λcr. However, if tensile tractions are not allowed on the interface, for λ > , λcr the layer separates from the interface along a certain finite region. First the continuous contact problem is reduced to singular integral equations and solved numerically using appropriate Gauss-Chebyshev integration formulas. Initial separation loads, λcr, initial separation points, xcr, are determined. Also the required distance between the punches to avoid any separation between the punches and the layer is studied and the limit distance between punches that ends interaction of punches, is investigated. Then discontinuous contact problem is formulated in terms of singular integral equations. The numerical results for initial and end points of the separation region, displacements of the region and the contact stress distribution along the interface between elastic layer and half plane is determined for various dimensionless quantities. [ABSTRACT FROM AUTHOR]

A globally convergent iterative algorithm for computing the spatial deformations of elastic beams without tensile strength is presented. The core of the algorithm is an iterative scheme (consistent with the classical Kirchhoff rod theory) for locating the neutral axis and thus for determining the curvature. We prove uniqueness and local stability for the general case and global stability for symmetric cross sections. The scheme is embedded in an iteration-free global boundary value problem solver (the so-called Parallel Hybrid Algorithm) to determine spatial equilibrium configurations. The obvious applications are steel reinforced concrete beams and columns, with or without pre-stressing. [ABSTRACT FROM AUTHOR]

Copyright of Technological & Economic Development of Economy is the property of Vilnius Gediminas Technical University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract: The suspen-dome system is a new structural form that has become popular in the construction of long-span roof structures. These domes are very slender and lightweight, their configuration is complicated, and hence sequential consideration in the structural design is needed. This paper focuses on these considerations, which include the method for designing cable prestress force, a simplified analysis method, and the estimation of buckling capacity. Buckling is one of the most important problems for dome structures. This paper presents the findings of an intensive buckling study of the Lamella suspen-dome system that takes geometric imperfection, asymmetric loading, rise-to-span ratio, and connection rigidity into consideration. Finally, suggested design and construction guidelines are given in the conclusion of this paper. [Copyright &y& Elsevier]

A deformed state of parabolic shape suspension cable subjected to asymmetric loading is under consideration. The cable kinematic nature of vertical and horizontal displacements, resulted from complementary asymmetrically distributed load are investigated, the expressions for their maximum values are derived. The deformability of suspension cable versus its curvature increment is investigated. The possibilities to stabilise the primary parabolic shape of suspension cable subjected to an asymmetric load are examined. Numerical simulation results are presented. [ABSTRACT FROM AUTHOR]

Low back injury is associated with sudden movements and loading. Trunk motion after sudden loading depends on the stability of the spine prior to loading and on the trunk muscle activity in response to the loading. Both factors are not axis-symmetric. Therefore, it was hypothesized that the effects on trunk dynamics would be larger after an asymmetric than after a symmetric perturbation. Ten subjects lifted a crate in which, prior to lifting, a mass was displaced to the front or to the side without the subjects being aware of this. Crate and subject movements, crate reaction forces and muscle activity were recorded. From this, the stability prior to the perturbation was estimated, and the trunk angular kinematics and moments at the lumbo-sacral joint were calculated. Both perturbations only minimally affected the trunk kinematics, although the stability of the spine prior to the lifting movement was higher in the sagittal plane than in the frontal plane. In both conditions the stability appeared to be sufficient to absorb the applied perturbation. [Copyright &y& Elsevier]

Theory of resonant frequency of an annular ring antenna with asymmetric multiple shorting posts is presented using modified Cavity Model. The posts are thin in diameter with respect to the diameter of ring. For accurate formulation, the shorting posts have been considered as inductive impedances at the frequency of interest. It is shown that for asymmetric loaded ring, TM11 is the dominant mode. The simple tool presented can be suitably modified to incorporate switching diodes or varactor diodes. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2351–2353, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23673 [ABSTRACT FROM AUTHOR]

The mean stress effect in fatigue life varies by material and loading conditions. Therefore, a classical low cycle fatigue (LCF) model based on mean stress correction shows limits in asymmetric loading cases in both accuracy and applicability. In this paper, the effect of strain ratio (R) on LCF life is analyzed and a strain ratio-based model is presented for asymmetric loading cases. Two correction factors are introduced to express correlations between strain ratio and fatigue strength coefficient and between strain ratio and fatigue ductility coefficient. Verifications are conducted through four materials under different strain ratios: high-pressure tubing steel (HPTS), 2124-T851 aluminum alloy, epoxy resin and AZ61A magnesium alloy. Compared with current widely used LCF models, the proposed model shows a better life prediction accuracy and higher potential in implementation in symmetric and asymmetric loading cases for different materials. It is also found that the strain ratio-based correction is able to consider the damage of ratcheting strain that the mean stress-based models cannot. [ABSTRACT FROM AUTHOR]