Showing papers on "Portal frame published in 1998"

Automatic packing machine with several different wrapping tapes of various widths

Abstract: This invention relates to a machine for automatic packing of products featuring a fixed portal frame in correspondence with the wrapping station used to support and move several wrapping tapes with different width, whose ends are wound up to form two reels, one fixed in upper position and one mobile in lower position.

Análise estrutural de pórticos planos de elementos pré-fabricados de concreto considerando a deformabilidade das ligações

Abstract: SOARES, A.M.M. (1998). Structural analysis of precast concrete portal frames considering the semi-rigid behavior of the connections. Sao Carlos. Dissertacao (Master Degree Thesis) Escola de Engenharia de Sao Carlos, Universidade de Sao Paulo. The use of precast concrete structures has increased in Brazil. Among them, the precast concrete portal frames with sloping beams have been extensively used in storehouses and commercial and industrial buildings. This type of portal frame, as the most precast concrete structures, has semirigid connections. So, this work deals with the study of the semi-rigid behavior of one beam-column connection type frequently used in these structures. In this kind of connection the beam rests on a corbel which has two projecting bolts connecting it. The aim of this thesis is also to determine the influence of the flexibility connection on the structure behavior. Numerical modeling applying the Finite Element Method and experimental tests were done to analyse these aspects. The test results of a beam-column model allowed the construction of the moment-rotation diagram and the failure mode

Nonlinear FE Analyses of RC Bridge Frame Corners, Based on Fracture Mechanics

Abstract: Reinforced concrete frame corners were analyzed using the nonlinear finite-element method and fracture mechanics. The objective of the study was to determine whether the reinforcement detailing in frame bridges could be simplified, with preserved structural safety, by splicing the reinforcement within the frame corner. A constitutive model for concrete, based on nonlinear fracture mechanics and plasticity, was used. An interface model was used to account for slip between the reinforcement and surrounding concrete. Analysis of previously tested frame specimens, with both spliced and unspliced corner reinforcement, was used to study the overall behavior of the frames; more detailed analysis of only the frame corner regions was used to study the influence of the reinforcement splices. The analyses were found to reflect the mechanical behavior of the specimens, and are in good agreement with the test results. The analysis results support, together with the test results, the idea that it would be feasible to splice all reinforcement in a portal frame bridge within the corner regions.

Assembling hoist device

Abstract: PROBLEM TO BE SOLVED: To provide an assembling hoist device which can be easily assemble and disassembled without using a particularly heavy machine. SOLUTION: A device comprises two portal frames 4 connecting a pair of columnar units 3 capable of opening a leg respectively in a cross member 2, a wheel device 5 mounted at a veriable mounting angle in a lower part of each columnar unit 3, a tensile means 6 for moving the columnar unit 3 of each portal frame 4 from a leg opened condition to a vertically standing condition, a pair of cross connecting frames 8 for forming a square frame 7 by connecting between upper parts of each portal frame 4, a cross bridge member 9 mounted capable of being mounted/demounted in/from the square frame 7, and a hoist means 12 directly or indirectly suspended in the cross bridge member 9.

Full Scale Experiments of a Steel Portal Frame Building

Abstract: While numerous full scale experimental programs have been conducted around the world over the past 50 years to investigate the behaviour of steel portal frame buildings, none have comprehensively investigated the behaviour of such buildings under wind uplift Wind uplift loads often govern designs in the Australian environment and this became the subject of a recent research project at Queensland University of Technology (OUT) This paper describes the full scale experiments on a steel portal frame building subject to wind uplift, racking and gravity loads The portal rafter and column members utilised hollow flange beam (HFB) sections [5-8] though the paper's findings on the theoretical and experimental building responses relate to conventional types of steel portal frame buildings

Composite working machine

Abstract: PROBLEM TO BE SOLVED: To simplify the treatment of chips during the drilling operation, to prevent chips from being scattered, and to prevent breakage of the equipment with chips by performing the drilling operation at the prescribed position in the material moving system. SOLUTION: A work moving and positioning device 5 provided with a clamp device 29 capable of holding and opening a work loaded on a work table 3, a drill head is provided on a fixing portal frame 7 which is fixed astride the work table 3, and a thermal cutting head 13 is provided on a moving portal frame 11 capable of being approached/separated to/from the fixing portal frame 7. Because the drilling is performed at the prescribed fixed position, chips generated during the drilling operation can be easily treated, and because the chips are prevented from being scattered over an upper surface of a work W, the thermally cutting head 13 can not be damaged.

Full scale experiments of a steel portal frame building

Abstract: While numerous full scale experimental programs have been conducted around the world over the past 50 years to investigate the behaviour of steel portal frame buildings, none have comprehensively investigated the behaviour of such buildings under wind uplift. Wind uplift loads often govern designs in the Australian environment and this became the subject of a recent research project at Queensland University of Technology (OUT). This paper describes the full scale experiments on a steel portal frame building subject to wind uplift, racking and gravity loads. The portal rafter and column members utilised hollow flange beam (HFB) sections [5-8] though the paper's findings on the theoretical and experimental building responses relate to conventional types of steel portal frame buildings.

Device for conveying concrete

Abstract: The utility model relates to a device for conveying concrete. An agitator and a winding engine are arranged on a same vehicle frame; a steel cable of the winding engine is connected with a lifting hopper guided by a lifting guide rail through a fixed pulley on the lifting guide rail; a horizontal guide rail is supported by a portal frame standing on a roof template; the bottom of an electric block on the horizontal guide rail is hung with a distributing hopper; the agitator directly discharges and conveys the concrete into the lifting hopper; the lifting hopper lifts to top along the lifting guide rail and automatically discharges and conveys the concrete into the distributing hopper running along the horizontal guide rail. The utility model is suitable for the mass concrete pouring of a building roof of less than three layers; the utility model has the advantages of labor saving, and high efficiency.

Application of a genetic algorithm and derivative-based techniques to identification of damage in steel structures

Abstract: Publisher Summary This chapter uses the output error method of system identification to assess the presence and extent of damage in steel structures. The identification problem is formulated as a following optimization problem: find parameters describing the presence and location of damaged elements in a structure by minimization of discrepancy of the modal response predicted by FE analysis from the test data. A typical portal frame has been chosen for experimental measurements. The dynamic response was measured by a piezoelectric accelerometer attached to the frame. The FE package ANSYS was used for the modal response analysis. Two choices of the optimization variables are considered, the first one produces a mixed discrete‑continuous problem solved by a Genetic Algorithm (GA), and the second results in a continuous problem solved by a combination of a GA used to produce a high-quality starting guess, and the Sequential Quadratic Programming (SQP) method modified for the use with noisy response function values. The proposed technique is illustrated by examples of recognition of damaged elements in a steel portal frame.

Repair of reinforced concrete portal frame damaged by alkali–silica reaction—strains after 5½ years

Abstract: In 1991 a two-level reinforced concrete portal frame, damaged by alkali�silica reaction, was repaired by demolishing and reconstructing the upper beam. Strain measurements at the junction of the old and new concretes showed very little differential movement over the next year. This brief article reports on strains that occurred during 4½ years from 1992 to 1996.

Temporary supporting method of pipeline frame

Abstract: PROBLEM TO BE SOLVED: To provide a method to temporarily support a pipeline with an existing support frame by a portal frame without providing a new support frame and to easily repair it by hanging and supporting the support frame of the pipeline by a hanging material hung down from a girder beam or a beam of the portal frame SOLUTION: A set of two supports 1, 1 is erected by keeping a specified distance from the outside of a support frame B of a popeline A and so that a head part of the support 1 is projected above the pipeline A Thereafter, a portal frame C is constructed by installing a girder 2 between the head parts of one set of the two supports 1, 1 and connecting it to the same supports 1, 1 A space is made between the same frame C and the pipeline A so that both of them do not make contact with each other Thereafter, the support frame B of the pipeline A is hung and supported by a beam 4 of the portal frame C straddling the pipeline A or a girder beam 3 or a hanging material 5 hung down from the girder 2 Consequently, it is possible to use the existing support frame B as it is, to eliminate setting of a new frame and to extremely economize it

Deck portal crane device

Abstract: PROBLEM TO BE SOLVED: To install a heavy object such as a gimbal sheave safely on the top of a portal type frame in a deck portal crane device. SOLUTION: A lifting wire 14 is suspended from the top part 2c of a deck portal type frame 2 so as to hoist a gimbal sheave 1 as a heavy object. While a guide metal fitting 11 is guided with a pair of guiding wires 5 tensed to engaging devices 6 on deck from brackets 3 inside the upper parts of both legs 2a of the portal frame 2, the gimbal sheave 1 is hoisted with the lifting wire 14, the protruding shafts on both sides of which are supported on receiving tools 12 in the brackets 3.

Frame with brace

Abstract: PROBLEM TO BE SOLVED: To provide a frame with a brace having capacity for absorbing the energy of external force by an earthquake, etc., and capable of preventing the damage of the frame. SOLUTION: In the frame with the braces, a pair of diagonal braces 31, 32 are stretched basically at the upper ends of columns 1b, 1a on the opposed sides obliquely from the lower ends of each column 1a, 1b in a portal frame constituted by bridging a beam 2 between a pair of the columns 1a, 1b. The frame with the braces is configured in such a manner that a pair of the diagonal braces 31, 32 are divided at central sections respectively to form split brace sections 31a, 31b, 32a, 32b at that time, these each split brace section 31a, 31b, 32a, 32b is extended in the axial directions and each of these extended front ends A, B, C, D is joined with the intermediate sections of other split brace sections 31a, 31b, 32a, 32b adjacent in the circumferential direction of the portal frame.

Portal frame unit

Abstract: A portal frame unit comprising an upright portion (12) and a roof portion (14) is manufactured from timber or a timber-based material and comprises lattice sections, which may be pivotally-interconnected to facilitate transport and assembly, and also to allow for variations in pitch of the roof. Two units are interconnected at their apices to form a complete frame. The individual lattice members, which may be solid or laminated, may contain insulating material.

Splice jointing behaviour in glulam portal frames

Abstract: The need for effective structural connections in glued laminated timber portal frames is discussed and the design of a flitch plate form of joint is outlined. Tests on the connection are described and its performance under flexure and shear is assessed. The influence of glueline thickness on joint performance is examined.

Inelastic Buckling Strength of Portal Frames Subjected to Beam Loads

Abstract: The effective length of a framed column is evaluated on the basis of the elastic buckling analysis of the frame in a conventional design, assuming the vertical load is applied on the centroid of the column, and the effect of the primary bending due to beam load is not considered. This paper presents the results of analysis of inelastic buckling strength of three types of portal frames subjected to beam loads, and the reduction of the buckling strength due to the beam load and the comparison with the strength evaluated by the conventional method are discussed.

Device for transporting paper reels, e.g. in paper mills

Abstract: The device comprises driven running gears (5) which are located at both front sides of the portal frame (2) of the device. The running movement of the running gears is transverse to the longitudinal travel direction of the transport device. The motor driven running gears are connected to the portal frame by inclined lift elements (10), so that they can be raised or lowered. The portal frame may be lifted by means of the lift elements.