Showing papers on "Bending moment published in 2013"
TL;DR: In this article, a numerical study was performed to investigate the factors that affect segmental tunnel lining behavior using a two-dimensional finite difference element model, where the longitudinal joint between segments in a ring has been simulated through double node connections, with six degrees of freedom represented by six springs.
156 citations
TL;DR: In this article, the authors investigated the time-dependent behavior of Shibli twin tunnels using laboratory testing, monitoring data, and finite difference numerical simulation approaches, and showed that after 55 years of tunnel utilization the compressive strengths of lining concrete will not be stable against the induced-stresses by thrust force and bending moment, thus the tunnel inspection and rehabilitation are recommended.
135 citations
TL;DR: The theoretical results are compared with some experimental findings available in literature and with the solution obtained from a commercial finite element software, and it is found that the first approach is capable of accurately evaluating the maximum deflection of the beam at failure.
88 citations
TL;DR: A finite element (FE) model of a vehicle occupant’s lower limb was developed in this study to improve understanding of injury mechanisms during traffic crashes and could be used in defining advanced injury criteria of the lower limb and in various applications as an alternative to physical testing.
Abstract: A finite element (FE) model of a vehicle occupant’s lower limb was developed in this study to improve understanding of injury mechanisms during traffic crashes. The reconstructed geometry of a male volunteer close to the anthropometry of a 50th percentile male was meshed using mostly hexahedral and quadrilateral elements to enhance the computational efficiency of the model. The material and structural properties were selected based on a synthesis of current knowledge of the constitutive models for each tissue. The models of the femur, tibia, and leg were validated against Post-Mortem Human Surrogate (PMHS) data in various loading conditions which generates the bone fractures observed in traffic accidents. The model was then used to investigate the tolerances of femur and tibia under axial compression and bending. It was shown that the bending moment induced by the axial force reduced the bone tolerance significantly more under posterior-anterior (PA) loading than under anterior-posterior (AP) loading. It is believed that the current lower limb models could be used in defining advanced injury criteria of the lower limb and in various applications as an alternative to physical testing, which may require complex setups and high cost.
84 citations
TL;DR: In this paper, a response evaluation of fractional visco-elastic Euler-Bernoulli beam under quasi-static and dynamic loads is presented, and it is shown that bending moment, curvature, shear, and the gradient of curvature involve fractional operators.
84 citations
TL;DR: In this paper, a combined hydrodynamic-structural design methodology for a commercial scale (1.5MW) turbine is presented, where a hydrodynamical analysis of the turbine blade is carried out to determine force distributions along the blade span under normal and extreme operating conditions.
83 citations
TL;DR: In this article, the static response of double-span beam-slab substructures bridging over a penultimate-internal (PI) column was investigated by a static loading scheme.
83 citations
TL;DR: In this paper, the steady-state response of an infinite beam resting on a visco-elastic foundation and subjected to a concentrated load moving with a constant velocity is investigated.
Abstract: SUMMARY
Analytical solutions for the steady-state response of an infinite beam resting on a visco-elastic foundation and subjected to a concentrated load moving with a constant velocity are developed in this paper. The beam responses investigated are deflection, bending moment, shear force and contact pressure. The mechanical resistance of the foundation is modeled using two parameters ks and ts — ks accounts for soil resistance due to compressive strains in the soil and ts accounts for the resistance due to shear strains. Since this model represents the ground behavior more accurately than the Winkler spring model, the developed solutions produce beam responses that are closer to reality than those obtained using the existing solutions for Winkler model. The dynamic beam responses depend on the damping present in the system and on the velocity of the moving load. Based on the study, dynamic amplification curves are developed for beam deflection. Such amplification curves for deflection, bending moment, shear force and contact pressure can be developed for any beam-foundation system and can be used in design. Copyright © 2012 John Wiley & Sons, Ltd.
79 citations
TL;DR: In this article, a mathematical model is proposed to investigate the dynamic response of an inclined single-walled carbon nanotube (SWCNT) subjected to a viscous fluid flow, where the tangential interaction of the inside fluid flow with the equivalent continuum structure (ECS) is taken into account via a slip boundary condition.
78 citations
TL;DR: In this paper, the authors analyse the ultimate strength of ageing ship structures based on experimental and numerical assessments and propose a relationship to calculate the equivalent tangent modulus as a function of the total reduction of the cross-sectional area due to corrosion degradation, which may be directly used as a master stress-strain curve for a nonlinear finite element analysis.
77 citations
TL;DR: In this paper, a modified Paik-Mansour formula for the ultimate strength calculation of ship hulls subject to vertical bending moments is proposed. But the method is based on a credible bending stress distribution over the hull cross-section presumed at the ultimate limit state.
Abstract: The objective of this paper is to develop a modified Paik–Mansour formula for the ultimate strength calculations of ship hulls subject to vertical bending moments. The method is based on a credible bending stress distribution over the hull cross-section presumed at the ultimate limit state. The accuracy of this method is demonstrated through comparison with computations obtained using more refined methods, such as non-linear finite-element method, intelligent super-size finite-element method, and idealised structural unit method. Statistical analysis of the hull girder ultimate strength based on comparisons among the various computations is carried out in terms of their mean values and coefficients of variation. The original Paik–Mansour method is found to be inapplicable to the case of a pure vertical bending moment depending on the ship's hull type and/or vertical bending direction, but the modified Paik–Mansour method is more general and is able to resolve this issue.
TL;DR: In this paper, a unified nonlocal shear deformation theory is proposed to study bending, buckling and free vibration of nanobeams based on the assumption that the in-plane and transverse displacements consist of bending and shear components.
Abstract: In this paper, unified nonlocal shear deformation theory is proposed to study bending, buckling and free vibration of nanobeams This theory is based on the assumption that the in-plane and transverse displacements consist of bending and shear components in which the bending components do not contribute toward shear forces and, likewise, the shear components do not contribute toward bending moments In addition, this present model is capable of capturing both small scale effect and transverse shear deformation effects of nanobeams, and does not require shear correction factors The equations of motion are derived from Hamilton\'s principle Analytical solutions for the deflection, buckling load, and natural frequency are presented for a simply supported nanobeam, and the obtained results are compared with those predicted by the nonlocal Timoshenko beam theory and Reddy beam theories
TL;DR: In this article, the authors revisited the problem of excavation of a circular lined tunnel in an infinite elastic medium under plane strain conditions, subjected to non-uniform stresses, solved by Einstein and Schwartz in their article ‘Simplified Analysis for Tunnel Supports’ published in 1979 (ASCE J Geotech Eng Div, 106-7), and in related publications by Schwartz and Einstein.
TL;DR: In this paper, a force-displacement mixed control quasi-static test on eight CFST columns subjected to combined compression, bending and torsion cyclic load was performed.
Abstract: Based on the force–displacement mixed control quasi-static test on eight CFST columns subjected to combined compression, bending and torsion cyclic load, the mechanical behavior of CFST columns with various section types, bending moment to torsion moment ratios and axial load levels was studied. The test results showed that the hysteretic curves of CFST columns under combined compression, flexure and torsion are plump due to the good seismic behavior and the ductility was also good. But for rectangular CFST columns with high bending moment to torsion moment ratio, the strength degradation was observed due to the local buckling of the steel plate at the bottom. The torsion capacity of CFST columns would be reduced by the bending moment. The plane section assumption of axial strain of CFST columns could be satisfied. The shear strain of the steel tube has good linear relationship with the rotation angle of the section when CFST columns subjected to combined compression, flexure and torsion. Based on the test results and literatures available, the mechanism of CFST columns was qualitatively analyzed.
TL;DR: In this article, a set of experimental tests of the hydrodynamic blade root out-of-plane bending moment response to planar oscillatory motion, chosen as an idealised representation of the unsteadiness imparted by waves and turbulence, is presented.
TL;DR: In this paper, the effects on the hoop force and bending moment developed in the lining of a circular tunnel of the contact properties of the soil-lining interface are investigated numerically for both cases of S- and P-seismic wave propagation.
TL;DR: In this paper, the role of a number of key phenomena controlling the amplitude of kinematic bending moments at the pile head was investigated by means of rigorous three-dimensional elastodynamic finite-element analyses.
Abstract: SUMMARY
Kinematic effects at the head of a flexible vertical pile embedded in a two-layer soil deposit are investigated by means of rigorous three-dimensional elastodynamic finite-element analyses. Both pile and soil are idealized as linearly viscoelastic materials, modelled by solid elements, without the restrictions associated with the use of strength-of-materials approximations. The system is analyzed by a time-Fourier approach in conjunction with a modal expansion in space. Constant viscous damping is considered for each natural mode, and an FFT algorithm is employed to switch from frequency to time domain and vice versa in natural or generalized coordinates. The scope of the paper is to: (a) elucidate the role of a number of key phenomena controlling the amplitude of kinematic bending moments at the pile head; (b) propose a simplified semi-analytical formula for evaluating such moments; and (c) provide some remarks about the role of kinematic bending in the seismic design of pile foundations. The results of the study provide a new interpretation of the interplay between interface kinematic moments and corresponding head moments, as a function of layer thickness, pile-to-soil stiffness ratio, and stiffness contrast between the soil layers. In addition, the role of diameter in designing against kinematic action, with or without the presence of an inertial counterpart, is discussed. Copyright © 2012 John Wiley & Sons, Ltd.
TL;DR: In this article, the failure of a clamped sandwich beam with a thin core is dominated by the bending moment, while the failure with a thick core fails by bending deformation in the front face sheet and the bottom face sheet in opposite direction.
Abstract: The dynamic response of clamped sandwich beam with aluminium alloy open-cell foam core subjected to impact loading is investigated in the paper. The face sheet and the core of the sandwich beam have the different thickness. And the sandwich beam is impacted by a steel projectile in the mid-span. The impact force is recorded by using accelerometer. The results show that tensile crack and core shear are the dominant failure modes. And the impact velocity and the thickness of the face sheet and the foam core have a significant influence on the failure modes and the impact forces. Combining with the inertia effect and experimental results, the failure mechanisms of the sandwich beams are discussed. The thickness of the foam core plays an important role in the failure mechanism of the sandwich beam. In present paper, the failure of the sandwich beam with a thin core is dominated by the bending moment, while the sandwich beam with a thick core fails by bending deformation in the front face sheet and the bottom face sheet in opposite direction due to the plastic hinges in the front face sheet.
TL;DR: In this article, a new damage index for plane steel frames under earthquake ground motion is proposed, which takes into account the interaction between the axial force N and bending moment M acting there.
TL;DR: In this article, a new one-dimensional model for the dynamic problem of magneto-electro-elastic generally laminated beams is presented, where electric and magnetic fields are assumed to be quasi-static and a first-order shear beam theory is used.
TL;DR: Laterally loaded piles are analyzed using the Fourier FEM as mentioned in this paper, where the analysis is performed for piles embedded in single-layer elastic soil with constant and linearly varying modulus and in two-layer linear elastic soil, with constant modulus within each layer.
Abstract: Laterally loaded piles are analyzed using the Fourier FEM. The analysis is performed for piles embedded in single-layer elastic soil with constant and linearly varying modulus and in two-layer elastic soil with constant modulus within each layer. The pile responses were observed to be functions of the relative stiffness of pile and soil, and of the pile slenderness ratio. Based on the analysis, equations describing pile head deflection, rotation, and maximum bending moment are proposed for flexible long piles and stubby rigid piles. These design equations are developed after plotting the pile responses as functions of pile-soil stiffness ratio and pile slenderness ratio. These plots can also be used as design charts. Design examples illustrating the use of the analysis are provided.
TL;DR: In this article, the authors developed a numerical model for a braced excavation to estimate the various design parameters that significantly influence the excavation's behavior, such as strutstiffness, wall thickness, and excavation depth.
Abstract: This paper discusses the development of a numerical model for a braced excavation to estimate the various design parameters that significantly influence the excavation's behavior. The results of the numerical model were compared with those of a reported case study of a braced excavation in sand, and close agreement between the results was observed. The developed model is used for parametric study to show theinfluenceofdifferentdesignparameters,suchasstrutstiffness,wallthickness,strutarrangementandtheembeddeddepthofthewallonstrut force, maximum moment developed in the wall, maximum lateral displacement of the wall, and maximum vertical displacement of ground surface.Itwasfoundthat,amongallthecombinationsstudied,aparticulartypeofstrutarrangementforaparticularratioofembeddeddepthand excavation depth produces the best possible result. A design guideline is also presented based on the results of this numerical study. DOI: 10.1061/(ASCE)GM.1943-5622.0000207. © 2013 American Society of Civil Engineers. CE Database subject headings: Bracing; Excavation; Displacement; Parameters; Struts; Walls; Bending; Numerical analysis. Author keywords: Braced excavation; FLAC; Stiffness; Displacement; Embedded depth; Design parameters; Strut force; Wall thickness; Wall bending moment.
TL;DR: In this paper, the authors derived the bending solutions of FGM Timoshenko beams in terms of the homogenous Euler-Bernoulli beams, by using mathematical similarity and load equivalence between the governing equations.
TL;DR: In this article, the fatigue behavior of composite steel and concrete beams subjected to negative bending moment was analyzed and the results indicated that when the repeated load was equivalent to the initial cracking load, the fatigue test had only limited influence on beam stiffness or crack patterns.
TL;DR: In this paper, an up-scaling procedure for computing the limit loads of spatial structures made of composite beams is proposed, where the resolution of an auxiliary yield design problem leads to the determination of a yield surface in the space of axial force and bending moments.
TL;DR: In this paper, a failure assessment diagram for strain-based fracture is presented for a pipeline with semi-elliptical surface cracks under large plastic bending, where the global strain is up to 3%.
TL;DR: In this article, the authors presented numerical analyses of semi-rigid joint systems in which the bolts are pretensioned, and the load-carrying mechanism of the socket joint system was investigated in detail through the numerical analysis.
TL;DR: In this paper, a liquid-structure interaction material model is developed and implemented in the OpenSees finite-element modeling platform for a single p-y element attached to a soil element, which is then used to analyze centrifuge experiments of a single pile in a level liquefiable profile and a six-pile group in a sloping liquefiability profile that resulted in lateral spreading.
Abstract: Liquefiable soil-structure interaction material models are developed and implemented in the open-source finite-element modeling platform OpenSees. Inputs to the free end of the p-y materials include the ground motion and mean effective stress time series from a free-field soil column. Example simulations using a single p-y element attached to a soil element demonstrate key features. The models are then used to analyze centrifuge experiments of a single pile in a level liquefiable profile and a six-pile group in a sloping liquefiable profile that resulted in lateral spreading. Measured displacements and mean effective stress time series are used as inputs to isolate the response of the material models from predictive uncertainties in free-field ground motion and excess pore pressure. The predicted pile response agrees reasonably well with measurements. The cyclic mobility behavior of sand in undrained loading is shown to be an important mechanism affecting bending moments in the piles; neglecting t...
TL;DR: In this paper, a new first-order shear deformation beam theory based on neutral surface position is developed for bending and free vibration analysis of functionally graded beams, which is based on assumption that the in-plane and transverse displacements consist of bending and shear components.
Abstract: In this paper, a new first-order shear deformation beam theory based on neutral surface position is developed for bending and free vibration analysis of functionally graded beams. The proposed theory is based on assumption that the in-plane and transverse displacements consist of bending and shear components, in which the bending components do not contribute toward shear forces and, likewise, the shear components do not contribute toward bending moments. The neutral surface position for a functionally graded beam which its material properties vary in the thickness direction is determined. Based on the present new first-order shear deformation beam theory and the neutral surface concept together with Hamilton\'s principle, the motion equations are derived. To examine accuracy of the present formulation, several comparison studies are investigated. Furthermore, the effects of different parameters of the beam on the bending and free vibration responses of functionally graded beam are discussed.
Patent•
12 Apr 2013TL;DR: In this paper, the bending moment is transferred to the outer skin via the frame member (59), and thus collapsing of the side sill (22) can be reliably inhibited without increasing the number and/or height of cross members.
Abstract: An inclined surface (19b) which extends in the front-rear direction to boundaries of a floor panel (25) and a side sill (22) is formed in an inner skin (19) of a fibre-reinforced plastic cabin for a vehicle As a result, when a bending moment (M) inwardly collapsing the side sill (22) in the vehicle width direction is exerted due to the impact force of a side-surface impact, collapsing of the side sill (22) can be inhibited without increasing the number and/or height of cross members (40) Furthermore, an outer skin (20) and the inclined surface (19b) of the inner skin (19) are joined to a frame member (59) which extends in the front-rear direction As a result, deformation of the inclinded surface (19b) can be inhibited Moreover, the bending moment (M) is consequently transferred to the outer skin (20) via the frame member (59), and thus collapsing of the side sill (22) can be more reliably inhibited