• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 한국전산구조공학회 2002년도 봄 학술발표회 논문집
• /
• pp.107-114
• /
• 2002

This paper deals with the non-linear analysis of cantilever beams with constant volume. Numerical methods are developed for solving the elastica of cantilever ben subjected to a tip Point load and a tip couple. The linear, parabolic and sinusoidal tapers with the regular polygon cross-section are considered, whose material volume and span length are always held constant. The Runge-Kutta and Regula-Falsi methods, respectively, are used to integrate the governing differential equations and to compute the unknown value of the tip deflection. The numerical results obtained herein are shown in tables and figures. Also the shapes of strongest beams are determined by reading the minimum values form the deflection versus section ratio curves.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 한국전산구조공학회 2002년도 봄 학술발표회 논문집
• /
• pp.115-122
• /
• 2002

The main purpose of this paper is to determine the static optimal shapes of tapered beams with constant volume. The linear, parabolic and sinusoidal tapers with the regular polygon cross-section are considered, whose material volume and span length are always held constant. The Runge-Kutta method is used to integrate the differential equation and also Shooting method is used to calculate the unknown boundary condition. Then the static optimal shapes are determined by reading the minimum values of the deflection versus section ratio curves plotted by the deflection data. In numerical examples, the various tapered beams are analyzed and those numerical results of this study are shown in figures.

• Journal of Korean Association for Spatial Structures
• /
• 제17권1호
• /
• pp.41-47
• /
• 2017

Structures of steel frame buildings getting vary depending on the development of construction technology. Fire-resistant steel beams and Columns accredited by accreditation bodies from the performance of various fire-resistant coating is applied to the current pillar method is most H-beams. H-beam has been proposed a non-load test specifications in the relevant regulations, its scope of accreditation to be granted without limitation of size H-beams from the performance of the test specification. However, in the case of the rectangular steel structure is to check its performance and to a separate one of the receive acknowledge and so take advantage of the cross-sectional shape factor in this study to test the performance of the fire-resistant structure proposed for standard test specimen.

• Proceedings of the Korea Concrete Institute Conference
• /
• 한국콘크리트학회 2006년도 추계 학술발표회 논문집
• /
• pp.193-196
• /
• 2006

Unlike external bonded plate or carbon fiber, the external unbonded strengthening has some advantages in speed and simplicity of installation. It is not required surface preparations and not affected by environmental conditions. A set of six laboratory tests on RC beams strengthened using the technique are reported, results compared with non-strengthened specimens. The main test parameters are the cross-sectional area of the high-tension bar and the distance of stirrups. Test result show that the beams reinforced are superior to reference specimens, especially for the strength and deformation capacity. Also, it is shown that good efficiencies can be achived in shear strength of the beam.

• Structural Engineering and Mechanics
• /
• 제51권5호
• /
• pp.773-792
• /
• 2014

In this paper, we study the inverse mode shape problem for an Euler-Bernoulli beam, using an analytical approach. The mass and stiffness variations are determined for a beam, having various boundary conditions, which has a prescribed polynomial second mode shape with an internal node. It is found that physically feasible rectangular cross-section beams which satisfy the inverse problem exist for a variety of boundary conditions. The effect of the location of the internal node on the mass and stiffness variations and on the deflection of the beam is studied. The derived functions are used to verify the p-version finite element code, for the cantilever boundary condition. The paper also presents the bounds on the location of the internal node, for a valid mass and stiffness variation, for any given boundary condition. The derived property variations, corresponding to a given mode shape and boundary condition, also provides a simple closed-form solution for a class of non-uniform Euler-Bernoulli beams. These closed-form solutions can also be used to check optimization algorithms proposed for modal tailoring.

• Structural Engineering and Mechanics
• /
• 제10권2호
• /
• pp.165-180
• /
• 2000

An analytical model with tension softening for the prediction of the capacity of prestressed concrete beams under pure torsion and under torsion combined with shear and flexure is introduced. The proposed approach employs bilinear stress-strain relationship with post cracking tension softening branch for the concrete in tension and special failure criteria for biaxial stress states. Further, for the solution of the governing equations a special numerical scheme is adopted which can be applied to elements with practically any cross-section since it utilizes a numerical mapping. The proposed method is mainly applied to plain prestressed concrete elements, but is also applicable to prestressed concrete beams with light transverse reinforcement. The aim of the present work is twofold; first, the validation of the approach by comparison between experimental results and analytical predictions and second, a parametrical study of the influence of concentric and eccentric prestressing on the torsional capacity of concrete elements and the interaction between torsion and shear for various levels of prestressing. The results of this investigation presented in the form of interaction curves, are compared to experimental results and code provisions.

• Structural Engineering and Mechanics
• /
• 제27권3호
• /
• pp.347-363
• /
• 2007

Assessment of structural behaviour of corrosion affected structures is an important issue, which would help in making certain decisions pertaining to the inspection, repair, strengthening, replacement and demolition of such structures. The paper presents formulations to predict the loss of weight and the loss of cross-sectional area of the reinforcing bar undergoing corrosion based on the earlier study carried out by the present authors (Bhargava et al. 2006). These formulations have further been used to analytically evaluate the ultimate bending moment and ultimate shear force capacity of the corroded concrete beams. Results of the present study indicate that, a considerably good agreement has been observed between the experimental and the analytically predicted values for the weight loss and reduction in radius of the corroded reinforcing bars. A considerably good agreement has also been observed between the experimental and the analytically predicted values of ultimate bending moment and ultimate shear force capacity for the corroded concrete beams.

• Geomechanics and Engineering
• /
• 제18권5호
• /
• pp.555-566
• /
• 2019

The purpose of this paper is to investigate the thermal effects on the behaviour reinforced-concrete beams strengthened by bonded angle-ply laminated composites laminates plate $[{\pm}{\theta}n/90m]_S$. Effects of number of $90^{\circ}$ layers and number of ${\pm}{\theta}$ layers on the distributions of interfacial stress in concrete beams reinforced with composite plates have also been studied. The present results represent a simple theoretical model to estimate shear and normal stresses. The effects the temperature, mechanical properties of the fibre orientation angle of the outer layers, the number of cross-ply layers, plate length of the strengthened beam region and adhesive layer thickness on the interfacial shear and normal stresses are investigated and discussed.

• Journal of the Korean Professional Engineers Association
• /
• 제16권4호
• /
• pp.4-14
• /
• 1983

when one is designing a continuous bridge with variable cross sections, it is very troublesome to integrate explicitly load terms and various factor under consideration so that it has different moment of inertia at each cross section. In this paper to obtain the influence line of a arbitary-span continuous beam with variable cross sections, the value of some particular function due to a load at any point can be carried out by numerical integration instead of definite integral. The ordinate of the influence line equals the product of the magnitude of the final moment at each support due to unit moment at any support and the load terms due to unit load, measured at the point of application of the load. It is concluded that this method can be easily used to design continuous bridges with arbitary cross sections.

• Steel and Composite Structures
• /
• 제37권3호
• /
• pp.353-369
• /
• 2020

Eight cold-formed thin-walled steel beams were performed to investigate the effect of corrosion damage on the flexural behavior of steel beams. The relationships between failure modes or load-displacement curves and corrosion degree of steel beams were investigated. A series of parametric analysis with more than forty finite element models were also performed with different corrosion degrees, types and locations. The results showed that the reduction of cross-section thickness as well as corrosion pits on the surface would lead to a decline in the stiffness and flexural capacity of steel beams, and gradually intensified with the corrosion degree. The yield load, ultimate load and critical buckling load of the corroded specimen IV-B46-4 decreased by 22.2%, 26% and 45%, respectively. The failure modes of steel beams changed from strength failure to stability failure or brittle fracture with the corrosion degree increasing. In addition, thickness damage and corrosion pits at different locations caused the degradation of flexural capacity, the worst of which was the thickness damage of compression zone. Finally, the method for calculating flexural capacity of corroded cold-formed thin-walled steel beams was also proposed based on experimental investigation and numerical analysis results.