Torsion of Reinforced Concrete Structural Members

2018 ◽  
Vol 272 ◽  
pp. 178-184
Author(s):  
Vladimír Křístek ◽  
Jaroslav Průša ◽  
Jan L. Vítek
Keyword(s):  
Bending Moments ◽  
Structural Elements ◽  
Structural Members ◽  
Structural System ◽  
Shear Forces ◽  
Axial Forces ◽  
Methods Of Calculation ◽  
Tensile Forces ◽  
Torque Capacity ◽  
The Common

According to the common design methods of calculation of the stress state induced by torsion of massive prismatic concrete structural elements, the structural system is reduced to a simple cage consisting of ties and struts. This model has, however, a number of principal shortcomings, the major of them is the fact that all of simultaneously acting effects like axial forces, bending moments and shear forces are not taken into account – the compressive axial forces increase very significantly the torque capacity of structural members, while due to action of tensile forces, bending moments and shear forces the torque capacity is reduced. These phenomena, applying non-linear approaches, are analysed and assessed.

scholarly journals Linear and Non-Linear Static Analysis of Berthing Structure

2020 ◽  
Vol 06 (09) ◽  
pp. 13-18
Author(s):  
K. Naga Sri Lakshmi and S Naveen Kumar
Keyword(s):  
Static Analysis ◽  
Influence Factors ◽  
Bending Moments ◽  
Structural Elements ◽  
Shear Forces ◽  
Axial Forces ◽  
Non Linear ◽  
Loading And Unloading ◽  
Beam Crane ◽  
Linear Static Analysis

Rapid growth in the water transport system demands the construction of more port and harbour structures.Berthing structures are constructed in ports and harbours to provide facilities such as berthing and mooring of vessels, loading and unloading of cargo and embarking and disembarking of passengers. Quays, wharfs, piers, jetties and dolphins are the most widely used berthing structures. In this project, linear and non-linear static analysis berthing structure module is studied. The basic data influence factors which affected the berthing structure were taken into consideration, such as soil characteristics of the proposed location, environmental conditions and range of traffic which will be used in the project is generally taken from Visakhapatnam port. The entire Berth length is 506.4m which is divided into 10 modules and each module length is 50.640m and width of the berth is 33.450m. The Berth has been analyzed by using STAAD Pro Software. After performing the linear and non-linear static analysis of the berthing structure module the behaviour of the structural elements is compared by various parameters deflection, bending moments, shear forces of cross beam, long beam, crane beam, front crane beam, retaining beam and also for the different piles. The axial forces variations of different piles are also studied.

scholarly journals Seismic Performance of Lightweight Concrete Structures

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Swamy Nadh Vandanapu ◽  
Muthumani Krishnamurthy
Keyword(s):  
Lightweight Concrete ◽  
Concrete Structures ◽  
Normal Weight ◽  
Bending Moments ◽  
Structural Members ◽  
Dead Load ◽  
Reinforced Concrete Frame ◽  
Shear Forces ◽  
Concrete Frame ◽  
Standard Software

Concrete structures are prone to earthquake due to mass of the structures. The primary use of structural lightweight concrete (SLWC) is to reduce the dead load of a concrete structure, which allows the structural designer to reduce the size of the structural members like beam, column, and footings which results in reduction of earthquake forces on the structure. This paper attempts to predict the seismic response of a six-storied reinforced concrete frame with the use of lightweight concrete. A well-designed six-storey example is taken for study. The structure is modelled with standard software, and analysis is carried out with normal weight and lightweight concrete. Bending moments and shear forces are considered for both NWC and LWC, and it is observed that bending moments and shear forces are reduced to 15 and 20 percent, respectively, in LWC. The density difference observed was 28% lower when compared NWC to LWC. Assuming that the section and reinforcements are not revised due to use of LWC, one can expect large margin over and above MCE (maximum considered earthquake; IS 1893-2016), which is a desirable seismic resistance feature in important structures.

scholarly journals DIFFERENT REINFORCEMENT TECHNIQUES IN DAMAGED BUILDINGS

2019 ◽  
Vol 2 (2) ◽  
pp. 211-219
Author(s):  
Altin Bidaj ◽  
Enio Deneko ◽  
Mario Hysenlliu
Keyword(s):  
Shear Capacity ◽  
Masonry Buildings ◽  
Masonry Structures ◽  
Bending Moments ◽  
Structural Elements ◽  
Shear Forces ◽  
Shear Strengthening ◽  
Repair Capacity ◽  
Externally Bonded ◽  
Real State

During their lifetime, the capacity of the single elements or of the entire structures is not anymore adequate to the static and dynamic functions requested by the project, mainly caused from deterioration of the masonry structures or the change of the destination and the purpose of the elements. Externally bonded FRP may be used in a repair capacity for structures that have moderate earthquakes damages or to reinforce structures considered to be vulnerable. The FRP strengthening systems are used mainly for flexural and shear strengthening of the structural elements subjected to bending moments and shear forces larger than their flexural and shear capacity, especially the beam-column joints. Many experiences in rehabilitation of damaged masonry buildings have been carried out in Europe in the last decades. Several unsuccessful results have underscored the need for adequate assessment prior to any rehabilitation. In fact, when neither the real state of damage nor the effectiveness of repairs is known, the results of the intervention are also unpredictable. In this article there are described different techniques used for reinforcement of masonry structures, with their advantages or disadvantages.

PERFORMANCE OF PRESTRESSED CONCRETE BEAM INCORPORATING AN AXIAL YIELD DAMPER USING UNBONDED REBAR

2020 ◽  
Vol 7 (2) ◽  
Author(s):  
Yuki Shirai ◽  
Kazushi Shimazaki
Keyword(s):  
Energy Absorption ◽  
Prestressed Concrete ◽  
Absorption Capacity ◽  
Structural Elements ◽  
Structural Members ◽  
Equivalent Damping ◽  
Sufficient Energy ◽  
Tensile Forces ◽  
Continuous Use ◽  
Hysteresis Characteristics

Unbonded prestressed concrete (UBPC) has shown considerable promise for structural elements in continuous-use applications. However, little research has evaluated the performance of UBPC structural elements or their low energy absorption ability, and such elements are therefore not commonly used as main structural members. In this study, a small axially yielding hysteresis damper was developed, which can be replaced in the event of earthquake damage to a UBPC beam in high continuous use. The damper was designed to use the axial yielding of deformed rebars so that it has the same performance under compressive and tensile forces. It was mounted in a knee brace shape and had a mass of about 10 kg. The damper exhibited positive and negative hysteresis characteristics even after the deformed rebars had yielded axially and it had sufficient energy absorption capacity. In a structural experiment, installing the damper, the shear force that can be borne by the beam and the equivalent damping constant increased, which means that the damper is useful.

Equivalent Design Wave Approach for Calculating Site-Specific Environmental Loads on an FPSO

2011 ◽  
Author(s):  
Resmi Sarala ◽  
Mohammad Hajiarab ◽  
Richard Bamford
Keyword(s):  
Spectral Characteristics ◽  
Vertical Acceleration ◽  
Bending Moments ◽  
Shear Forces ◽  
Environmental Loads ◽  
Extreme Loads ◽  
Sea Current ◽  
Industry Practice ◽  
The Common ◽  
Wind Sea

This paper demonstrates the method used by Lloyd’s Register (LR) to derive an equivalent design wave from a response based analysis (RBA) to represent extreme loads on a weather-vaning FPSO [1] and proceeds to compare the results with that of the industry practice of the response amplitude operator (RAO) based approach. The responses investigated include roll, pitch, vertical wave bending moments, vertical wave shear forces and vertical acceleration. The RBA is based on 3 hourly hindcast metocean data and uses the results of the heading analysis directly, considering the combined effect of wind, wind-sea, current and swell. An equivalent design wave is then derived based on the spectral characteristics of each response instead of the common practice for ship design [2] which uses only the characteristics of the RAOs. For each response the design wave for the RBA and RAO approaches is compared. Deriving equivalent design waves using only the RAO characteristics is found to give some non-conservative and unrealistic equivalent design waves in some cases.

scholarly journals Overview of the modified magnetoelastic method applicability

ACTA IMEKO ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 167
Author(s):  
Tomáš Klier ◽  
Tomáš Mícka ◽  
Michal Polák ◽  
Milan Hedbávný
Keyword(s):  
Prestressed Concrete ◽  
Concrete Structures ◽  
Engineering Practice ◽  
Structural Elements ◽  
Engineering Structures ◽  
Advantages And Disadvantages ◽  
Axial Forces ◽  
Technical Practice ◽  
Tensile Forces

<p class="Abstract">A requirement of axial force determination in important structural elements of a building or engineering structure during its construction or operational state is very frequent in technical practice. In civil engineering practice, five experimental techniques are usually used for evaluation of axial tensile forces in these elements. Each of them has its advantages and disadvantages. One of these methods is the magnetoelastic method, that can be used, for example, on engineering structures for experimental determination of the axial forces in prestressed structural elements made of ferromagnetic materials, e.g., prestressed bars, wires and strands. The article presents general principles of the magnetoelastic method, the magnetoelastic sensor layout and actual information and knowledge about practical application of the new approach based on the magnetoelastic principle on prestressed concrete structures. Subsequently, recent results of the experimental verification and the in-situ application of the method are described in the text. The described experimental approach is usable not only for newly built structures but in particular for existing ones. Furthermore, this approach is the only one effectively usable experimental method for determination of the prestressed force on existing prestressed concrete structures in many cases in the technical practice.</p>

scholarly journals Parametric Analysis of the Shear Lag Effect in Tube Structural Systems of Tall Buildings

2020 ◽  
Vol 11 (1) ◽  
pp. 278
Author(s):  
Ivan Hafner ◽  
Anđelko Vlašić ◽  
Tomislav Kišiček ◽  
Tvrtko Renić
Keyword(s):  
Parametric Analysis ◽  
Numerical Models ◽  
Tall Buildings ◽  
Structural Systems ◽  
Structural Elements ◽  
Structural System ◽  
Shear Lag ◽  
Shear Lag Effect ◽  
Lag Effect ◽  
Secondary Structural Elements

Horizontal loads such as earthquake and wind are considered dominant loads for the design of tall buildings. One of the most efficient structural systems in this regard is the tube structural system. Even though such systems have a high resistance when it comes to horizontal loads, the shear lag effect that is characterized by an incomplete and uneven activation of vertical elements may cause a series of problems such as the deformation of internal panels and secondary structural elements, which cumulatively grow with the height of the building. In this paper, the shear lag effect in a typical tube structure will be observed and analyzed on a series of different numerical models. A parametric analysis will be conducted with a great number of variations in the structural elements and building layout, for the purpose of giving recommendations for an optimal design of a tube structural system.

Large Deflection of a Rectangular Plate Resting on a Pasternak-Type Elastic Foundation

1977 ◽  
Vol 44 (3) ◽  
pp. 509-511 ◽  
Author(s):  
P. K. Ghosh
Keyword(s):  
Rectangular Plate ◽  
Elastic Foundation ◽  
Large Deflection ◽  
Lateral Load ◽  
Bending Moments ◽  
Shear Forces ◽  
Simply Supported ◽  
Base Parameters ◽  
Square Plate

The problem of large deflection of a rectangular plate resting on a Pasternak-type foundation and subjected to a uniform lateral load has been investigated by utilizing the linearized equation of plates due to H. M. Berger. The solutions derived and based on the effect of the two base parameters have been carried to practical conclusions by presenting graphs for bending moments and shear forces for a square plate with all edges simply supported.

scholarly journals The verification of a new approach to the experimental estimation of tensile forces in prestressed structural elements by method based on the magnetoelastic principle

2017 ◽  
Vol 107 ◽  
pp. 00015 ◽  
Author(s):  
Tomáš Klier ◽  
Tomáš Míčka ◽  
Tomáš Plachý ◽  
Michal Polák ◽  
Tomáš Smeták ◽  
...  
Keyword(s):  
Structural Elements ◽  
New Approach ◽  
Experimental Estimation ◽  
Tensile Forces

scholarly journals 3-D Numerical Study of Mechanical Behaviors of Pile-Anchor System

2014 ◽  
Vol 580-583 ◽  
pp. 238-242
Author(s):  
Ri Cheng Liu ◽  
Bang Shu Xu ◽  
Bo Li ◽  
Yu Jing Jiang
Keyword(s):  
Simulation Analysis ◽  
Numerical Study ◽  
Bending Moments ◽  
Mechanical Behaviors ◽  
Foundation Pit ◽  
Anchor System ◽  
Anchor Cable ◽  
Axial Forces ◽  
Toppling Failure ◽  
Potential Failure

Mechanical behaviors of pile-soil effect and anchor-soil effect are significantly important in supporting engineering activities of foundation pit. In this paper, finite difference method (FDM) was utilized to perform the numerical simulation of pile-anchor system, composed of supporting piles and pre-stressed anchor cables. Numerical simulations were on the basis of the foundation pit of Jinan’s West Railway Station, and 3D simulation analysis of foundation pit has been prepared during the whole processes of excavation, supporting and construction. The paper also analyzed the changes of bending moments of piles and axial forces of cables, and discussed mechanical behaviors of pile-anchor system, through comparisons with field monitoring. The results show that the parameters concluding vertical gridding’s number, cohesion of pile and soil, and pile stiffness have robust influences on supporting elements’ behaviors. Mechanical behaviors of supporting pile and axial forces of anchor cable changed dramatically, indicating that the potential failure form was converted from toppling failure to sliding failure.

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