Positive Moment Research Articles

Construction Sequence Analysis and Conventional Lumped Analysis considering P-Delta Effect by Using Etabs

While analyzing a multistorey building frame, conventionally all the probable loads are applied after modeling the entire building frame. But in practice the frame is constructed in various stages. Accordingly, the stability of frame varies at every construction stage. Even during construction freshly placed concrete floor is supported by previously cast floor by formwork. Thus, the loads assumed in conventional analysis will vary in transient situation. Obviously, results obtained by the traditional analysis will be unsuitable. Therefore, the frame should be analyzed at every construction stage taking into account variation in loads. The phenomenon known as Construction Sequence Analysis considers these uncertainties precisely. Therefore, the building structure should be analysed at every stage of construction taking into account the load variations. In this project two cases have been considered. Whereas in Case 1 the multistoried building (G+22 storied) with floating columns and transfer girder will be analysed by response spectrum method and considering P-delta effect as a whole for the subjected loading and in Case 2 the multistoried building (G+22storied) with floating columns and transfer girder will be analysed by response spectrum method with reference to the construction sequence or staged construction and considering P-delta effect. In the present study a G+22 storey multistoried R.C.C building model is modelled using Etabs 2019 software. Response spectrum analysis is made by considering building situated in zone III.Building models are analyzed by Etabs 2019 software to study the effect of maximum positive moment, maximum negative moment, maximum shear forces, maximum deflection, maximum torsion moment of transfer girder beam and total axial load under transfer girder and floating column etc

NEOLOGISMS FORMATION AND USE IN THE NOVEL «1984» BY G. ORWELL

Objective of the article is to analyze the peculiarities of the formation and use of neologisms in Orwell’s novel «1984». Methods. The main scientific results are obtained using a set of general scientific and special research methods, namely: analysis, generalization and systematization of scientific and educational literature on literary studies, psychology, and linguistics; theoretical generalization, analysis and synthesis, as well as comparative, descriptive and analytical Results. Enrichment of language with new lexical units of any type and structure is a positive moment in the process of development and improvement of the language and language tools. It is the emergence of neologisms that indicates the development of society and humanity as a whole. Neologisms, on the one hand, are defined as words, meanings, or combinations of words that have appeared in a particular language over a period. On the other hand, neologisms are terms that are a new meaning of an existing word, or a word borrowed from another language, the novelty of which is still felt. According to linguists, neologisms are words of any period that are new to the previous period; not only new words, but also new meanings of words, as well as new phraseological or stable word combinations; units arising from the elements of the language existing in the language. Based on the study, we concluded that on the pages of his novel, J. Orwell manages to portray and recreate a world in which all generally accepted humane principles are reversed, universally recognized human values are absent, but still not defeated human nature itself, which inevitably seeks to break out, discovering ways to overcome unbearable shackles. In addition, the shackles that society as a whole and each individual are trying to envelop, the representatives of this inhuman regime with an unconditional dictatorship of power. It should be emphasized that there is no one correct way to translate neologisms, especially authorial ones. At the same time, the socio-political conditions in which the translator finds himself may limit the choice of a suitable translator for reasons of censorship or political expediency. To ensure the adequacy of the translation of works with a pronounced linguistic and cultural component, the translator must be aware of the realities of both cultures: the culture of the source text and the culture of the target one.

Influence of Vehicle Number on the Dynamic Characteristics of High-Speed Train-CRTS III Slab Track-Subgrade Coupled System.

In this paper, a high-speed train–CRTS III slab track–subgrade coupled dynamic model is established. With the model, the influence of vehicle number on the dynamic characteristics of a train–CRTS III slab track–subgrade coupled system with smooth and random track irregularity conditions for conventional and vibration-reduction CRTS III slab tracks are theoretically studied and analyzed. Some conclusions are drawn from the results: (1) the largest dynamic responses of the coupled system for all items and cases are no longer changed when the vehicle number exceeds three, and three vehicles are adequate to guarantee the simulation precision to investigate the dynamic responses of the coupled system. (2) The acceleration of the car body has almost no relation with the vehicle number, and only one vehicle is needed to study the vehicle dynamics using the train–CRTS III slab track–subgrade coupled dynamic model. (3) For the conventional CRTS III slab track on a subgrade, the vehicle number has a negligible influence on the accelerations of the rail, slab, and concrete base, the positive and negative bending moments of the rail, the compressive force of the fastener, and the positive bending stress of slab, but it has a large influence on the tension force of the fastener, and the negative bending stresses of the slab and concrete base. Only one vehicle is needed to study track dynamics without considering the tension force of the fastener, the negative bending stresses of the slab and concrete base, otherwise, two or more vehicles are required. (4) For vibration reduction of the CRTS III slab track on a subgrade, the number of vehicles has some influence on the dynamic responses of all track components, and at least two vehicles are required to investigate the track dynamics.

Creating Solutions for Meeting the Challenges of Maintaining a Healthy Work Practice: Our Experience at a County Hospital

Creating Solutions for Meeting the Challenges of Maintaining a Healthy Work Practice: Our Experience at a County Hospital

Investigation of piled behaviour due to an adjacent excavation: 3D numerical modelling

Zameer Ahmed Channaret al.,InternationalJournal of Emerging Trends in Engineering Research, 9(6), June 2021, 683–689683ABSTRACTIn congested cities, excavations are unavoidably constructed adjacent to high rising building supported by piled raft foundations which reduces differential settlements in the buildings. Since the excavations inevitably induce soil movement and stress changes in the ground, it may cause differential settlements to nearby piled raft foundation. In this numerical study, a 3D coupled consolidation numerical analysis (using a hypoplastic model, which considers strain dependent and path-dependent soil stiffness) was conducted to investigate a (2×2) piled raft responses to an adjacent 25-m deep excavation in saturated clay. The computed results have revealedthat the rate of piled raft settlement increased significantly beyond excavation stage h/He=0.5. This is because of the degradation of stiffness of clay with strain due to excavation-induced stress release. Differential settlement (i.e. tilting) was induced in the piled raft due to non-uniform stress release.Owing to separation of the raft from the ground due excavation, some of the working load was transferred to the four piles. The maximum positive bending moment was 200 kNm at Z/Lp=0.67. However, no any bending moment was induced in both the piles at the toes.

Flexural behavior analysis on RC simply supported girder strengthened by adding diagonal brace

Adding the diagonal bracing to strengthen RC simply supported beam bridge has certain engineering application space. In order to study the flexural performance of the strengthened members, the finite element model was established by Midas/Civil to calculate and analyze the load effect of 20m span RC simply-supported T beam under 12 flexural strengthening conditions. The results showed that the connection form of diagonal brace has little influence on the deformation behavior of the strengthened beam. After reinforcement, the positive moment and deflection of mid-span of the main beam can be reduced by more than 50%. At the same time, the main beam appears negative moment, horizontal reaction force, and vertical negative reaction force may occur. The reasonable arrangement of the brace position can ensure that the main beam does not have vertical negative reaction force, and the main beam negative moment and horizontal reaction force, the horizontal and vertical reaction force of the diagonal brace are controlled to obtain ideal load effect results.

Geometrically thick tori around compact objects with a quadrupole moment

We study geometrically thick perfect-fluid tori with constant specific angular momentum, so-called ‘Polish doughnuts’, orbiting deformed compact objects with a quadrupole moment. More specifically, we consider two different asymptotically flat, static and axisymmetric vacuum solutions to Einstein’s field equation with a non-zero quadrupole moment, the q-metric and the Erez–Rosen spacetime. It is our main goal to find features of Polish doughnuts in these two spacetimes which qualitatively distinguish them from Polish doughnuts in the Schwarzschild spacetime. As a main result we find that, for both metrics, there is a range of positive (Geroch–Hansen) quadrupole moments which allows for the existence of double tori. If these double tori fill their Roche lobes completely, their meridional cross-section has the shape of a fish, with the body of the fish corresponding to the outer torus and the fish-tail corresponding to the inner torus. Such double tori do not exist in the Schwarzschild spacetime.

Development and Verification of the Capacity Curve for Two Dimensional Reinforced Concrete Moment-Resisting Frames System under Earthquake Loading

Pushover analysis is an efficient method for the seismic evaluation of buildings under severe earthquakes. This paper aims to develop and verify the pushover analysis methodology for reinforced concrete frames. This technique depends on a nonlinear representation of the structure by using SAP2000 software. The properties of plastic hinges will be defined by generating the moment-curvature analysis for all the frame sections (beams and columns). The verification of the technique above was compared with the previous study for two-dimensional frames (4-and 7-story frames). The former study leaned on automatic identification of positive and negative moments, where the concrete sections and steel reinforcement quantities the source of these moments. The comparison of the results between the two methodologies was carried out in terms of capacity curves. The results of the conducted comparison highlighted essential points. It was included the potential differences between default and user-defined hinge properties in modeling. The effect of the plastic hinge length and the transverse of shear reinforcement on the capacity curves was also observed. Accordingly, it can be considered that the current methodology in this paper more logistic in the representation of two and three-dimensional structures.

Numerical and FEA investigation of sectional capacity and moment redistribution behavior of steel fiber reinforced concrete (SFRC) beam

Steel fiber reinforced concrete exhibits ductility. This ductility behavior enables redistribution of moment between the negative and positive moment zones in continuous SFRC beams. The sectional capacity of an SFRC continuous beam was determined using the moment-curvature response, the ductility of the member using the moment-rotation response, and the moment redistribution behavior using the moment-rotation response. The theoretical moment-curvature response was calculated from the stress-strain response for 0 % (control), 0.5 %, 0.75 %, and 1.5 % SFRC member which served the basis for the defined moment-rotation behavior and FEA. A five-point bending test was conducted on a two-span beam using a constitutive material model in the FEA software package, Abaqus/CAE. The concrete damage plasticity (CDP) model was used to conduct a displacement-controlled analysis on the fully integrated 3D hexahedral element (C3D8). The numerical study revealed that the flexural behavior, bending capacity, rotation capacity, and ductility of the 0.5 %, 0.75 %, and 1.5 % SFRC beams were significantly enhanced than the 0 % SFRC beam. However, as steel fiber volume increased, the quantity of moment redistribution in the SFRC beam decreased. The amount of moment redistribution obtained was 21.8 % for 0 %, 19 % for 0.5 %, 18.1 % for 0.75 %, and 13.9 % for 1.5 % SFRC.

On Markov Moment Problem and Related Results

We prove new results and complete our recently published theorems on the vector-valued Markov moment problem, by means of polynomial approximation on unbounded subsets, also applying an extension of the positive linear operators’ result. The domain is the Banach lattice of continuous real-valued functions on a compact subset or an Lν1 space, where ν is a positive moment determinate measure on a closed unbounded set. The existence and uniqueness of the operator solution are proved. Our solutions satisfy the interpolation moment conditions and are between two given linear operators on the positive cone of the domain space. The norm controlling of the solution is emphasized. The most part of the results are stated and proved in terms of quadratic forms. This type of result represents the first aim of the paper. Secondly, we construct a polynomial solution for a truncated multidimensional moment problem.

Test and Numerical Model of Curved Steel-Concrete Composite Box Beams under Positive Moments.

Compared with straight steel–concrete composite beams, curved composite beams exhibit more complicated mechanical behaviors under combined bending and torsion coupling. There are much fewer experimental studies on curved composite beams than those of straight composite beams. This study aimed to investigate the combined bending and torsion behavior of curved composite beams. This paper presents static loading tests of the full elastoplastic process of three curved composite box beams with various central angles and shear connection degrees. The test results showed that the specimens exhibited notable bending and torsion coupling force characteristics under static loading. The curvature and interface shear connection degree significantly affected the force behavior of the curved composite box beams. The specimens with weak shear connection degrees showed obvious interfacial longitudinal slip and transverse slip. Constraint distortion and torsion behavior caused the strain of the inner side of the structure to be higher than the strain of the outer side. The strain of the steel beam webs was approximately linear. In addition, fine finite element models of three curved composite box beams were established. The correctness and applicability of the finite element models were verified by comparing the test results and numerical calculation results for the load–displacement curve, load–rotational angle curve, load–interface slip curve, and cross-sectional strain distribution. Finite element modeling can be used as a reliable numerical tool for the large-scale parameter analysis of the elastic–plastic mechanical behavior of curved composite box beams.

Modal and harmonic response analysis of new CFRP laminate reinforced concrete railway sleepers

Nowadays high-cost sleeper applications are becoming indispensable because of railway operation conditions and high frequency train loads. For the protection of sleepers and other railway components, “non-prestressed” sleepers have the potential to reduce railway maintenance costs and exhibit a longer service life compared to their prestressed competitors. But the disadvantage of this process is steel reinforcement defects due to corrosion and fatigue. A new type of sleeper with non-pre-stressing process with non-corroding carbon fiber reinforced polymer (CFRP) laminate reinforcements can overcome these disadvantages. Rail seat static positive moment tests have been performed for these new types of sleepers before and it was determined that they can provide the desired static strength parameters even in high speed train lines. In this study, modal and harmonic response analysis has been performed and the results compared with prestressed sleepers with equivalent concrete cross-section dimensions. According to the results this new sleeper model has higher damping advantages and is expected to be beneficial in extending the service life of the railway components, reducing maintenance needs, and harmful effects on the environment.

Effect of sports shoe mileage on running mechanics and lower limb muscular activities in male individuals with and without genu varus

The aim of the present study was to evaluate the long-term effects of shoes wearing on lower limb kinetics and electromyography activity of selected muscles of genu varus males compared with healthy age-matched controls during running. Equipment and methods Fifteen healthy males (age: 23.20 ± 1.78 years) and 14 males with genu varus (age: 21.57 ± 2.34 years) were eligible for inclusion in this study. Participants received new shoes before the baseline test and were measured with the same shoes (used shoes) after six months in the post-test. Ground reaction forces and muscle activities were recorded in both pre-test and post-test during running. Irrespective of the groups, pair-wise comparisons revealed that peak medial ground reaction force (p = 0.002; d = 0.316) values were higher at post-test. Furthermore, peak negative free moment (p = 0.008; d = 0.235) and peak positive free moment (p < 0.002; d = 0.298) were higher and lower respectively at the post-test. For electromyography activity at the loading phase, the tibialis anterior and vastus medialis muscle activities were higher in the post-test, while the vastus medialis, vastus lateralis, and rectus femoris muscles activities were higher at the mid-stance phase. The gluteus medius muscle activity was reduced at the push-off phase in the post-test. Shoe mileage appears to have an impact on ground reaction force and selected muscle activities in healthy male individuals with and without genu varus. Together with the observed findings on shoe stiffness, it seems appropriate to change running shoes after a great wearing time of approximately six months with walking and to run mileage about 17 km/week. Le but de la présente étude était d’évaluer les effets à long terme du port de chaussures sur la cinétique des membres inférieurs et l’activité électromyographique de certains muscles de genu varus mâles par rapport à des témoins sains en fonction de l’âge pendant la course. Quinze hommes en bonne santé (âge: 23,20 ± 1,78 ans) et 14 hommes atteints de genu varus (âge: 21,57 ± 2,34 ans) étaient éligibles à l’inclusion dans cette étude. Les participants ont reçu de nouvelles chaussures avant le test de base et ont été mesurés avec les mêmes chaussures (chaussures usagées) après six mois dans le post-test. Les forces de réaction au sol et les activités musculaires ont été enregistrées à la fois avant et après les tests pendant la course. Indépendamment des groupes, des comparaisons par paires ont révélé que les valeurs maximales de la force de réaction au sol médiane (p = 0,002; d = 0,316) étaient plus élevées au post-test. De plus, le moment libre négatif maximal (p = 0,008; d = 0,235) et le moment libre positif maximal (p <0,002; d = 0,298) étaient respectivement plus élevés et plus faibles au post-test. Pour l’activité d’électromyographie à la phase de chargement, les activités musculaires du tibial antérieur et du vaste médial étaient plus élevées dans le post-test, tandis que les activités des muscles du vaste médial, du vaste latéral et du rectus fémoral étaient plus élevées à la phase intermédiaire. L’activité musculaire du fessier moyen a été réduite lors de la phase de poussée dans le post-test. Le kilométrage des chaussures semble avoir un impact sur la force de réaction au sol et certaines activités musculaires chez les individus masculins en bonne santé avec et sans genu varus. Parallèlement aux résultats observés sur la rigidité des chaussures, il semble approprié de changer de chaussures de course après une grande durée de port d’environ six mois avec un kilométrage à pied et à pied d’environ 17 km/semaine.

Novel Bending Test Method for Polymer Railway Sleeper Materials.

Alternative sleeper technologies have been developed to address the significant need for the replacement of deteriorating timber railway sleepers. The review of the literature indicates that the railway sleepers might fail while in service, despite passing the evaluation tests of the current composite sleeper standards which indicated that these tests do not represent in situ sleeper on ballast. In this research, a new five-point bending test is developed to evaluate the flexural behaviour of timber replacement sleeper technologies supported by ballast. Due to the simplicity, acceptance level of evaluation accuracy and the lack of in-service behaviour of alternative sleepers, this new testing method is justified with the bending behaviour according to the Beam on Elastic Foundation theory. Three timber replacement sleeper technologies—plastic, synthetic composites and low-profile prestressed concrete sleepers in addition to timber sleepers—were tested under service loading condition to evaluate the suitability of the new test method. To address the differences in the bending of the sleepers due to their different modulus of elasticities, the most appropriate material for the middle support was also determined. Analytical equations of the bending moments with and without middle support settlement were also developed. The results showed that the five-point static bending test could induce the positive and negative bending moments experienced by railway sleepers under a train wheel load. It was also found that with the proposed testing spans, steel-EPDM rubber is the most suitable configuration for low bending modulus sleepers such as plastic, steel-neoprene for medium modulus polymer sleepers and steel-steel for very high modulus sleepers such as concrete. Finally, the proposed bending moment equations can precisely predict the flexural behaviour of alternative sleepers under the five-point bending test.

The Development of Extradosed Bridge Concept from a Vision to a Reality

The development of Extradosed bridge from a vision to a real project is presented in this paper. Mathivat of France who is recognized as the inventor of this bridge type, envisioned a new bridge type suitable for medium span ranges in 1979. He suggested that some of the cantilever tendons in balanced cantilever bridge can be deviated to the top deck supported by short tower resemble stay cables. The structural benefit of this idea is increasing positive moment capacity by increasing eccentricity over the pier and enhanced shear capacity. Therefore, with the same conditions, longer span can be designed. Due to small angle of stay cables, the cable allowable stress at serviceability is about the same level with balanced cantilever bridge and no significant penalty on fatigue resistance unlike stay cables for conventional cable stayed bridges. The Extradosed bridge offers economic benefit for medium span range and aesthetically pleasing.

Moments of Connection for the Disconnected: People with Negative Relations with Others Experience Less, but Benefit More from, Positive Everyday Interaction

Analysis of over 2,000 moments of social interaction collected through smartphone-based experience sampling showed that, over a week-long period, people who have experienced negative relations with others (relative to those who have not), interacted with individuals from less-established relationships, perceived less partner responsiveness during interactions (particularly from their established relationship partners), and were more likely to report being alone than engaged in positive communication episodes. People with high negative relations with others also tended to have lower perceptions of affective well-being and relational connection, and greater perceptions of stress-related cognition, during moments of social interaction. Yet, results also indicated that while positive communication appears harder to come by for people with high negative relations with others, these individuals gain outsized benefits from positive interaction when it occurs (e.g., sharper increases in well-being and decreases in stress). This suggests that heightened negative relations with others might lead people to “hyperabsorb” the benefits of positive moments of communication. The results have implications for key perspectives on communication, relational life, and well-being (i.e., affection deprivation, appraisal, implicit vigilance, and resource insufficiency) and suggest potential routes for intervention development for people with difficult relational lives.

Moment Redistribution in Continuous Externally CFRP Prestressed Beams with Steel and FRP Rebars.

This paper assesses the impact of adopting carbon- or glass-fiber-reinforced polymer (CFRP or GFRP) instead of steel rebars on the redistribution of moments in prestressed concrete beams (PCBs) with external CFRP tendons. A numerical program is introduced, and numerical simulations are performed on two-span continuous beams with steel, CFRP or GFRP rebars of various areas, i.e., Ar2 = 360–3560 mm2, and Ar1/Ar2 = 1.5, where Ar1 and Ar2 are areas of tensile rebars over the positive and negative moment zones, respectively. The results show the moment redistribution is contributed by concrete cracking only for the beams with fiber-reinforced polymer (FRP) rebars, and by concrete cracking and steel yielding for the beams with steel rebars. As a result, the use of FRP rebars leads to a substantially lower moment redistribution than in steel rebars. It is also demonstrated that Eurocode 2, CSA A23.3-04 and ACI 318-19 fail to reflect the rebar influence on moment redistribution in PCBs with external tendons. A simplified equation for the quantification of moment redistribution in externally PCBs with steel and FRP rebars is recommended, which yields accurate and conservative predictions.

Measurement of the Positive Muon Anomalous Magnetic Moment to 0.46ppm.

We present the first results of the Fermilab National Accelerator Laboratory (FNAL) Muon g-2 Experiment for the positive muon magnetic anomaly a_{μ}≡(g_{μ}-2)/2. The anomaly is determined from the precision measurements of two angular frequencies. Intensity variation of high-energy positrons from muon decays directly encodes the difference frequency ω_{a} between the spin-precession and cyclotron frequencies for polarized muons in a magnetic storage ring. The storage ring magnetic field is measured using nuclear magnetic resonance probes calibrated in terms of the equivalent proton spin precession frequency ω[over ˜]_{p}^{'} in a spherical water sample at 34.7 °C. The ratio ω_{a}/ω[over ˜]_{p}^{'}, together with known fundamental constants, determines a_{μ}(FNAL)=116 592 040(54)×10^{-11} (0.46ppm). The result is 3.3 standard deviations greater than the standard model prediction and is in excellent agreement with the previous Brookhaven National Laboratory (BNL) E821 measurement. After combination with previous measurements of both μ^{+} and μ^{-}, the new experimental average of a_{μ}(Exp)=116 592 061(41)×10^{-11} (0.35ppm) increases the tension between experiment and theory to 4.2 standard deviations.

MODIFIED WEB SLENDERNESS CLASSIFICATION FOR COMPOSITE GIRDERS IN CODE PROVISIONS

Composite girder is one of the main structural systems used in bridges and buildings. The same slenderness limits requirements for steel sections are used also for the composite sections in most specifications without considering the effect of concrete slabs. In fact, for composite sections under positive moments, the compression concrete slab restrains the buckling of the top flange and the compressed part of the web, in addition the steel plates behave plastically up to failure. By accounting concrete slabs attached to the steel compression elements, the section may be placed in more favorable class. The main objective of this study is to verify a reasonable relaxed slenderness limits for steel compact composite sections compared to compact steel section only and investigate the influences of the span length of girder and the concrete strength of slab, on the slenderness limits. An extensive parametric study using ANSYS, a commercial finite element (FE) software, was held using different web slenderness, various concrete strengths and girder lengths. The section classifications were evaluated, and the results were compared to the Egyptian code, Eurocode and AASHTO.A new relaxed equation and new classification limits have been developed considering the effect of the concrete slab strength.

Reconfigurable Curved Beams for Selectable Swimming Gaits in an Underwater Robot

Rowing is a swimming motion employed by a number of animals via tuned passive biomechanics and active gait strategies. This gait generates positive net thrust (or moment) by having a higher drag profile in the power stroke compared with the recovery stroke, which is obtained via faster actuation speed or higher effective area. In this letter, we show that using the preferential buckling of curved beams in swimming robots can, via a passive reduction of effective area in recovery stroke, be used to generate positive net thrust and moment. Additionally, these curved beams can be actively tuned to alter their behavior on demand for use in swimming applications, and can be used in an underwater robot to switch between rowing and flapping gaits. A dynamic model has been developed to model the swimming behavior of a robot using buckling joints. A design optimization has been carried out, using the Covariance Matrix Adaption Evolution Strategy (CMA-ES), to find the design and gait parameters that maximize the robot's forward swimming speed. A series of experimental gait searches have subsequently been conducted on the resulting optimal design, again using CMA-ES with the goal of finding the optimal gait pattern across a number of swimming strategies such as paddling, flapping, and undulation. By actively altering the curved beam's buckling limits, an untethered robot has been developed that maneuvers in water across each of these swimming strategies. The findings suggest that tuning the preferential buckling limits of curved beams can be an effective and potentially advantageous approach for producing directional thrust and moments.