Bearing Capacity Analysis for Statically Indeterminate Attachment System of Tower Crane Considering Single Limb Instability

2013 ◽  
Vol 446-447 ◽  
pp. 463-468
Author(s):  
Nian Li Lu ◽  
Shu Rui Wen
Keyword(s):  
Local Buckling ◽  
Internal Force ◽  
Calculation Model ◽  
Critical Force ◽  
Unit Load ◽  
Tower Crane ◽  
Unit Load Method ◽  
Internal Forces ◽  
Attachment Device ◽  
The Moment

The tower cranes need constantly attaching to rise in the construction of high-rise buildings. The tower body which sets attached frames combined with the four-rod-type unilateral statically indeterminate attachment system is a common form. With the attachment height and distance increasing, the attachment rods become more delicate and flexible. It is necessary to check the overall and local stability of the attachment structure. When a single limb instability happens, the reduced-order variation structure brings about the redistribution of internal forces. The anti-buckling capability depends on the structure of variation. To the condition that the single limb instability occurrs on the component which has the weakest stiffness, an exact internal force expression of the structure under composite loads has been deduced in terms of the moment equilibrium method. At the same time, the decoupling support stiffnesses of the attachment device in each direction have been obtained by the unit load method. Based on the refined calculation model, the internal forces are further analyzed under the condition that the instability rod bears the fixed Euler critical force, and the structural strength and stability capacity has been judged. The calculation result proves that the whole structure has great bearing potential after a local buckling.

Solving Internal Forces of Piles of Jointless Bridges under the Action of Temperature Using Ordinary Differential Systems

2014 ◽  
Vol 1082 ◽  
pp. 220-223
Author(s):  
Dan Lv ◽  
Da Jun Zhao ◽  
Long Li ◽  
Chuan Feng Zheng
Keyword(s):  
Differential Equations ◽  
Internal Force ◽  
Calculation Model ◽  
The Finite Element Method ◽  
Bridge Abutments ◽  
Differential Systems ◽  
Jointless Bridges ◽  
Scientific Approach ◽  
Internal Forces ◽  
Force Equilibrium

Temperature effect has a great effect on the force and deformation of bridge abutments, piles and filling at back abutment of jointless bridges. It’s necessary to definitude calculation model when using the finite element method to analyze these matter, but there is still no scientific approach to design jointless bridges. A method that solving internal forces of piles of jointless bridges under the action of temperature using ordinary differential equations is advanced in this paper. Differential equation of each rod of jointless bridges is established based on material mechanic, and then all differential equations form a differential systems. The internal force and deformation of the bridge are getted by solving differential equations based on boundary conditions, deformation coordination of rod coupling points and internal force equilibrium conditions, which is clear and definite.

Research on Calculation Method of Internal Force Caused by Seasonal Temperature Difference in All-Vertical-Piled Wharf

2014 ◽  
Vol 1065-1069 ◽  
pp. 503-508
Author(s):  
Jun Jie Wang ◽  
Liang De He ◽  
Zhi Ming Zhang ◽  
Zhe Jiang Li
Keyword(s):  
Temperature Stress ◽  
Temperature Difference ◽  
Calculation Method ◽  
Internal Force ◽  
Calculation Model ◽  
Seasonal Temperature ◽  
Pile Diameter ◽  
Internal Forces ◽  
Foundation Pile ◽  
The One

When the wharf structure is completed, the temperature is different with the one at the usage period. The temperature difference will lead to the temperature strain, and create the lateral deformation and internal forces of the piles. Based on the assumption of the free temperature difference of beam-slab-system, the spatial simplified calculation model of the foundation pile and the stiff platform about the temperature stress in all-vertical-piled wharf is first proposed, the related calculation method is also given. The numerical example shows that the accuracy of this simplified method could meet the demand of preliminary design. In order to reduce the pile-top internal forces, the foundation piles should be arranged symmetrically. The pile-top internal forces are in direct proportion to the forth power of the pile diameter, with the increase of the pile diameter in all-vertical-piled wharf, the analysis of the temperature stress must be taken seriously.

scholarly journals Pembesaran Gaya Dalam dan Rasio Kekuatan Elemen Struktur Baja untuk berbagai Zona Gempa di Indonesia. (Hal. 74-84)

2019 ◽  
Vol 5 (1) ◽  
pp. 74
Author(s):  
Kamila Shaomi Nazila ◽  
Kamaludin Kamaludin
Keyword(s):  
Steel Structure ◽  
Internal Force ◽  
Building Structure ◽  
Force Analysis ◽  
Earthquake Loads ◽  
Load Variations ◽  
Earthquake Load ◽  
Magnification Ratio ◽  
Internal Forces ◽  
The Moment

ABSTRAKStruktur bangunan dapat dikatakan kuat jika dapat memikul semua beban salah satunya, beban gempa. Waktu mendesain struktur akibat beban gempa lebih lama daripada akibat beban tanpa gempa. Penelitian ini bertujuan untuk memprediksi pembesaran gaya dalam dan prediksi rasio kekuatan pada struktur akibat adanya beban tanpa gempa. Penelitian ini dilakukan terhadap gedung 10 lantai dengan material baja. Tujuh model variasi beban pada gedung sebagai berikut: beban tanpa gempa,beban tanpa gempa dan percepatan 0,2 ; 0,4 ; 0,6 ; 0,8 ; 1,0 ; juga 1,2 . Analisis gaya dalam dan pengecekan kekuatan struktur bangunan menggunakan software ETABS 2015. Hasil yang diperoleh pada balok yaitu, gaya lentur ( ) dengan pembesaran momen maksimum kurang lebih 0,9 kali terhadap momen akibat beban tanpa gempa. Pembesaran momen relatif antar variasi beban kurang lebih 1,2. Hal ini mengakibatkan rasio untuk desain awal kurang lebih 30% untuk daerah gempa kuat.Kata kunci: struktur baja, beban gempa, pembesaran momen, pembesaran rasio. ABSTRACTThe structure of the building can be said to be strong if it can carry all the loads, such as the earthquake loads. Time to design structures due to earthquake loads is longer than without earthquakes loads. This study aims to predict the magnification of internal forces and the ratio of strength to structures due to without earthquake loads. This research was conducted on 10-storysteel building. Seven models of load variations in the building are as follows: load without earthquake, load without earthquake and acceleration of 0.2 , 0.4 , 0.6 , 0.8 , 1.0 , and 1.2 . The internal force analysis and checking of building structure strengthare using ETABS 2015. The results obtained that flexural force ( ) with a maximum moment magnification of approximately 0.9 times the moment due to without earthquake loads on the beam. Enlargement of relative moments between load variations is approximately 1.2. Therefore, ratio of the initial design is approximately 30% for strong earthquake areas. Keywords: steel structure, earthquake load, moment magnification, ratio enlargement.

Finite Element Analysis of Continuous Curved Box-Girder Bridge

2013 ◽  
Vol 454 ◽  
pp. 183-186
Author(s):  
Qi Yong You
Keyword(s):  
Finite Element ◽  
Internal Force ◽  
Calculation Model ◽  
Box Girder Bridges ◽  
Element Analysis ◽  
Box Girder ◽  
Girder Bridges ◽  
Internal Forces ◽  
Box Girder Bridge ◽  
Girder Bridge

The calculations of plan truss and beam-girder method on straight bridge were analyzed, which determined right beam-girder method calculation model of the box-girder bridge. Based on this model, the different radius continuous curved box-girder bridges were simulated by finite element, and then the internal forces of the bridge were obtained. The calculations of inner beam and outer beam show the change rule of internal force and bridge radius. The reasonable calculation methods of continuous curved box girder bridges are obtained, which can offer help to the bridge designers.

A Convenient Method for Calculating Internal Force of Rod for Tower Crane

2013 ◽  
Vol 853 ◽  
pp. 541-546
Author(s):  
Yuan Xue ◽  
Da Qi Wu ◽  
Bin Kou ◽  
Nian Li Lu
Keyword(s):  
Finite Element ◽  
Spatial Structure ◽  
Efficient Method ◽  
Convenient Method ◽  
Internal Force ◽  
Calculation Model ◽  
Truss Structure ◽  
The Real ◽  
Finite Element Software ◽  
Tower Crane

This paper made an assumption which considered the structure of tower crane as truss structure and equated the complex spatial structure of tower body under multi-loads to single planar truss structure. The calculation model of internal force of rods was built. The calculation formulas of four types of trellis tower mast configuration commonly used were derived. The result based on the real project given by the calculation formulas agreed with the result given by the finite element software. These explicitly expressed formulas were simple and easy to calculate by hand. An accurate and efficient method to calculate internal force of rods of tower crane was provided.

EVALUATION OF MOUNTAIN AREA AS NON-POINT SOURCE OF NITROGEN FOR SETO INLAND SEA: THE NORTHERN SHIKOKU REGION, JAPAN

2017 ◽  
Author(s):  
Shohei Morisawa ◽  
Shohei Morisawa ◽  
Yukio Komai ◽  
Yukio Komai ◽  
Takao Kunimatsu ◽  
...  
Keyword(s):  
Average Concentration ◽  
Point Sources ◽  
Seto Inland Sea ◽  
Mountain Streams ◽  
Unit Load ◽  
Mountain Areas ◽  
Mountain Area ◽  
The Seto Inland Sea ◽  
Unit Load Method ◽  
Important Position

The northern Shikoku region is located in the Western part of Japan and faces towards the Seto Inland Sea. The forest area, which is one of the non-point sources in the Seto Inland Sea watershed, occupies 75% of the land use in the watershed of the northern Shikoku region. The amount of loadings of nutrients and COD in the Seto Inland Sea has been estimated by the unit load method but actually the data has not been investigated. It is however, necessary to know the real concentration of nitrogen in mountain streams to evaluate the role which is the mountain area plays as non-point sources. Therefore, more water samples of mountain streams in the watershed need to be taken and the concentrations of nitrogen analyzed. The mountain streams in the northern Shikoku area were investigated from April, 2015 to November, 2015. The number of sampling sites was 283, in addition to the past data by Kunimatsu et al. The average concentration of nitrate nitrogen in Ehime, Kagawa, and Tokushima was 0.61mg/L, 0.78mg/L and 0.34mg/L, respectively. The environmental standard range for nitrogen in the Seto Inland Sea is from between less than 0.2mg/L and less than 1mg/L. Therefore, the average concentration of nitrogen in these regions was over category II, and those of mountain streams in Kagawa Prefecture exceeded category III. About 20% of mountain streams were more than 1mg/L. It has become clear that mountain areas occupy an important position as non-point sources for the Seto Inland Sea.

Structural Analysis and Internal Force Calculation of Variable Cross-Section Silo

2012 ◽  
Vol 446-449 ◽  
pp. 429-434
Author(s):  
Rui Ting Ma
Keyword(s):  
Cross Section ◽  
Variable Cross Section ◽  
Internal Force ◽  
Variable Cross ◽  
Axially Symmetric ◽  
Internal Forces ◽  
Differential Element ◽  
Symmetric Load ◽  
Force Calculation ◽  
Constant Section

In this paper, the differential element of constant-section silo wall suffering from axially symmetric load is analyzed. From the results of constant-section silo, the author derives the displacements and internal forces of variable cross-section silo. Through a specific example, this paper compares the displacements , internal forces and concrete consumption of variable cross-section silo with those of constant-section silo, and discusses the merits of variable cross-section silo.

Experimental Study on In-Plane Behavior of CFST Arch with New-Type Dumbbell-Shaped Section

2011 ◽  
Vol 255-260 ◽  
pp. 1198-1203 ◽  
Author(s):  
Ye Sheng
Keyword(s):  
Local Buckling ◽  
High Strength ◽  
Steel Tube ◽  
Calculation Model ◽  
Plastic Behavior ◽  
Loading Process ◽  
New Type ◽  
Set Up ◽  
Ultimate Load Carrying Capacity ◽  
Shaped Section

The weakness of traditional dumbbell-shaped section is that when concrete is filled into the web space, great stress is likely to produce cracks in the weld sealing between steel tube and web plates. In order to avoid this condition, a new-type dumbbell-shaped section is proposed. Experiments on concrete filled steel tubular (CFST) model arches with new-type dumbbell-shaped section have been carried out, concentrated loading at crown and L/4 section respectively. The result indicated that the new-type CFST arch has good elastic-plastic behavior and high strength, no local buckling appeared during the whole loading process, its in-plane mechanic behavior is similar with that of the CFST arch with single-tube. The dual nonlinear finite element calculation model is set up for the model arch, by means of this model the load-deflection curves during the loading process and the ultimate load-carrying capacity is analyzed.

scholarly journals DETERMINATION OF DEFORMABILITY PARAMETERS OF CONCRETE SAMPLES BY THE FORMULAS OF FRACTURE MECHANICS

2020 ◽  
Vol 11 (2) ◽  
pp. 88-98
Author(s):  
B. A Bondarev ◽  
N. N Chernousov ◽  
V. A Sturova
Keyword(s):  
Fracture Mechanics ◽  
Lower Surface ◽  
Local Deformation ◽  
Concrete Sample ◽  
Test Scheme ◽  
Limit Value ◽  
Bending Load ◽  
Internal Forces ◽  
The Moment ◽  
External Forces

To determine the deformability parameters of concrete samples by the formulas of fracture mechanics, equilibrium tests were carried out at the stage of local deformation of the sample, which showed the correspondence of the change in external forces to the internal forces of the material resistance with the corresponding static development of the main crack. For the same purpose, the samples are tested for bending with an initial notch and the “load-deflection” diagram is recorded. In this work, we presented a test scheme for a specimen with a notch (crack) and constructed a diagram of the deformation of a specimen under bending “load-deflection”. Based on it, it is possible to predict the destruction of the material, that is, to determine the value of the load at which the limit value of deflection or the displacement of the outer edges of the notch (opening the throat of the crack on the lower surface of the specimen) can be taken as the moment of loss of the resource of the material. Also, we examined the deformation of a concrete sample during three-point bending and presented a diagram of the deformation of a concrete sample within the plastic zone. Dependencies were derived for determining the ultimate relative strains under tension and bending. Based on the results obtained, the state diagrams of the stretched concrete and the deformation scheme of the normal section of the concrete sample were constructed. As a result, the conclusion and convergence of the results.

Sign in / Sign up

Export Citation Format

Share Document