Research on Post-Tensioned Unbonded Prestressed Concrete Hollowed Floor

2011 ◽  
Vol 94-96 ◽  
pp. 1456-1462
Author(s):  
Xiao Hua Yang ◽  
Chao Yang Zhou ◽  
Xue Jun He ◽  
Teng Chen
Keyword(s):  
Prestressed Concrete ◽  
Experimental Studies ◽  
Load Carrying Capacity ◽  
Structure Model ◽  
Test Results ◽  
Maximum Displacement ◽  
Element Analysis ◽  
Direction Parallel ◽  
Load Carrying ◽  
Post Tensioned

In order to study the mechanical behaviors of post-tensioned unbonded prestressed concrete hollowed floors, a 1/4 scale post-tensioned unbonded prestressed reinforced concrete hollow slab-column structure model is used to act uniform distributed load on the floor. The test results showed that the load carrying capacity is enough. The points of maximum displacement are at the centers of slabs. By means of the experimental studies and elastic finite element analysis methods, the results showed that post-tensioned unbonded prestressed concrete hollowed floor presents anisotropy with layout of circular-tubes in one way. In direction parallel to layout of hollowed tubes, the continuity of floor is destruction and bending stiffness of slab is weakened. For studying the deformations of slab, it can still be considered continuous cross-slab in two directions.

Experimental Studies on Bearing Capacity of Post-Tensioned Unbonded Prestressed Concrete Hollowed Floors

2011 ◽  
Vol 368-373 ◽  
pp. 159-163 ◽  
Author(s):  
Xiao Hua Yang ◽  
Chao Yang Zhou ◽  
Xue Jun He ◽  
Zhi Qing Yang
Keyword(s):  
Bearing Capacity ◽  
Prestressed Concrete ◽  
Plastic Hinge ◽  
Experimental Studies ◽  
Load Test ◽  
Test Results ◽  
Three Stages ◽  
Hinge Model ◽  
Good Agreement ◽  
Post Tensioned

A 1/4 scales four-storey model of post-tensioned unbonded prestressed concrete hollow slab-column structure has been made to do the ultimate load test on the second-storey floor. By measuring the floor deflection, stresses of steel bars and cracks of floors, the bearing capacity of floor is explored. The bearing capacity tests of floor are divided into three stages: elastic stage, crack growth stage and destruction stage. Based on the test results and crack developments in floor, a improved plastic hinge model is carried out to predict the ultimate loads. The calculated results of the ultimate loads with improved plastic hinge model are in good agreement with the experiment data.

Study on Ultimate Strength Analysis Method for SWATH Ships

2009 ◽  
Author(s):  
Bin Liu ◽  
Weiguo Wu
Keyword(s):  
Ultimate Strength ◽  
Structural Model ◽  
Strength Analysis ◽  
Test Model ◽  
Load Carrying Capacity ◽  
Test Results ◽  
Analysis Method ◽  
Element Analysis ◽  
Load Carrying ◽  
Ultimate Load Carrying Capacity

Nowadays, numerical calculation and structural model test are mainly applied in the ultimate strength analysis of ship structure. This paper presents the results of an ultimate strength test to determine the ultimate load-carrying capacity of an ocean-survey SWATH ship. A comparison between nonlinear FEA (finite element analysis) for test model and test results is presented. The FE-models of real ship and model ship as well as their relations are studied.

scholarly journals Post-fire serviceability and residual strength of composite post-tensioned concrete T-beams

2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Amer F. Izzet ◽  
Nazar Oukaili ◽  
Nibras A. Harbi
Keyword(s):  
Prestressed Concrete ◽  
Carrying Capacity ◽  
Static Loading ◽  
Concrete Beams ◽  
Load Carrying Capacity ◽  
Shear Connectors ◽  
Four Point Bending ◽  
Load Carrying ◽  
Fire Flame ◽  
Post Tensioned

AbstractIn this study, the response of ten composite post-tensioned concrete beams topped by a reinforced concrete deck with adequate reinforcing shear connectors is investigated. Depending on the concrete compressive strength of the deck slab (20, 30, and 40 MPa), beams are grouped into three categories. Seven of these beams are exposed to a fire attack of 700 and 800 °C temperature simultaneously with or without the presence of a uniformly distributed sustained static loading. After cooling back to ambient temperature, these composite beams are loaded up to failure, using a force control module, by monotonic static loading in a four-point-bending setup with two symmetrical concentrated loads applied in the middle third of the effective span. The objectives of this study include investigating the behavior of the composite prestressed concrete beams under and after the exposure to a direct fire flame, as well as finding their residual load-carrying capacity. Tests demonstrate significant deteriorations caused by exposure to high temperatures associated with the increase of the member’s camber. The increase of the midspan camber after heating exposure reached approximately 200%. On the other hand, the 1-h steady-state exposure of test specimens to temperatures of 700 and 800 °C led to reduce the load-carrying capacity of the heat-deteriorated beams up to 45% and 54%, respectively.

Ratchet Boundary Determination Using a Noncyclic Method

2010 ◽  
Vol 132 (2) ◽  
Author(s):  
R. Adibi-Asl ◽  
W. Reinhardt
Keyword(s):  
Elastic Moduli ◽  
Load Carrying Capacity ◽  
Structure Model ◽  
Stress Distributions ◽  
Radial Temperature Gradient ◽  
Element Analysis ◽  
Radial Temperature ◽  
Adjustment Procedure ◽  
Boundary Determination ◽  
Load Carrying

A simple and systematic procedure is proposed for shakedown analysis using a combination of linear and nonlinear finite element analysis (FEA). The method can identify the boundary between the shakedown and ratcheting domains directly and does not require a cyclic analysis (noncyclic). The proposed method performs an elastic-plastic FEA to determine the reduction in load carrying capacity due to the cyclic secondary loads. An elastic modulus adjustment procedure is then used to generate statically admissible stress distributions and kinematically admissible strain distributions under the applied primary loads. By modifying the local elastic moduli it is possible to obtain inelastic-like stress redistribution. The method is demonstrated with a “two-bar structure” model based on analytical routine. The analysis is then applied to some typical shakedown problems including the “classical Bree problem,” the “bimaterial cylinder,” and the “plate with a hole subjected to radial temperature gradient.”

Repair of steel structures by bonded carbon fibre reinforced polymer patching: experimental and numerical study of carbon fibre reinforced polymer – steel double-lap joints under tensile loading

2007 ◽  
Vol 34 (12) ◽  
pp. 1542-1553 ◽  
Author(s):  
Angus C.C. Lam ◽  
J.J. Roger Cheng ◽  
Michael C.H. Yam ◽  
Gaylene D. Kennedy
Keyword(s):  
Carbon Fibre ◽  
Lap Joints ◽  
Load Carrying Capacity ◽  
Test Results ◽  
Lap Joint ◽  
Element Analysis ◽  
Reinforced Polymer ◽  
Load Carrying ◽  
Carbon Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer

The behavior of carbon fibre reinforced polymer (CFRP) composite bonded to a steel plate double-lap joint was investigated experimentally. A total of 19 specimens were tested with the major test parameters being the bonded lap length, LL, and the axial adherend stiffness ratio, ETR. Five of the 19 specimens were prepared using CFRP sheets, and the rest using CFRP plates. Two CFRP plate specimens were prepared with a tapered lap joint, and their results were compared with those of counterpart specimens prepared without tapered lap joints. In general, the behavior of specimens made from either CFRP sheets or CFRP plates were similar. The joint's axial load carrying capacity increased with increasing LL up to a certain limit, when the joint's load carrying capacity could no longer be increased by increasing LL. However, experimental results showed that a larger failure deformation could be achieved by increasing LL past this limit. Specimens that had the same inner adherend thickness but higher axial adherend stiffness ratios showed higher axial load carrying capacities. Test results also showed that the strengths of tapered lap joints were almost the same as those of nontapered lap joints with the same LL. Nonlinear finite element analysis was carried out to study the stress–strain behavior of the adherend and the adhesive of the double-lap joint. Using finite element analysis results in an analytical solution obtained from the literature, predictions of the joint's maximum axial strength and minimum required LL were made. This analytical solution provided good predictions when compared with test results, producing test to predicted ratios from 0.88 to 1.14.

Experimental studies on bolted glubam connections

2021 ◽  
pp. 136943322110179
Author(s):  
R.Z. Yang ◽  
Y. Xiao
Keyword(s):  
Failure Modes ◽  
Experimental Studies ◽  
Tensile Tests ◽  
Load Carrying Capacity ◽  
Test Results ◽  
Laminated Bamboo ◽  
Load Carrying ◽  
End Distance ◽  
Compressive Testing ◽  
Compressive Tests

This paper reports tensile and compressive test results of bolted glubam (glued laminated bamboo) connections. The tensile tests were carried out with two types of specimens designed for tensile loadings in the longitudinal and transverse directions in relevance to the orientations of the bidirectional bamboo strips (fibers). In each direction, the specimens were further divided into nine groups according to different combination conditions of end and edge spacings. Compressive tests were executed for three groups of bolted glubam connections, with varying thickness of the main board and bolting conditions. The tensile experiments show that the failure of the specimens is strongly influenced by the loading directions. Recommended end distance and side distance are provided, whereas the load carrying capacity is analyzed. Based on the compressive testing results, failure modes and load displacement relationships are analyzed, in which the yield bearing capacity is shown to be close to that given by the equations in existing design specifications for timber structure.

Investigation of Burst Pressure in T-Joints With Wall-Thinning by Using FEA

2017 ◽  
Author(s):  
Atsushi Yamaguchi
Keyword(s):  
Carrying Capacity ◽  
Safety Margin ◽  
Pressure Vessels ◽  
Burst Pressure ◽  
Load Carrying Capacity ◽  
Working Pressure ◽  
Element Analysis ◽  
T Joints ◽  
Wall Thinning ◽  
Load Carrying

Boilers and pressure vessels are heavily used in numerous industrial plants, and damaged equipment in the plants is often detected by visual inspection or non-destructive inspection techniques. The most common type of damage is wall thinning due to corrosion under insulation (CUI) or flow-accelerated corrosion (FAC), or both. Any damaged equipment must be repaired or replaced as necessary as soon as possible after damage has been detected. Moreover, optimization of the time required to replace damaged equipment by evaluating the load carrying capacity of boilers and pressure vessels with wall thinning is expected by engineers in the chemical industrial field. In the present study, finite element analysis (FEA) is used to evaluate the load carrying capacity in T-joints with wall thinning. Burst pressure is a measure of the load carrying capacity in T-joints with wall thinning. The T-joints subjected to burst testing are carbon steel tubes for pressure service STPG370 (JIS G3454). The burst pressure is investigated by comparing the results of burst testing with the results of FEA. Moreover, the maximum allowable working pressure (MAWP) of T-joints with wall thinning is calculated, and the safety margin for the burst pressure is investigated. The burst pressure in T-joints with wall thinning can be estimated the safety side using FEA regardless of whether the model is a shell model or a solid model. The MAWP is 2.6 MPa and has a safety margin 7.5 for burst pressure. Moreover, the MAWP is assessed the as a safety side, although the evaluation is too conservative for the burst pressure.

DESIGN AND ANALYSIS OF AN INTEGRATED THREE- BAY THERMOPLASTIC COMPOSITE WINGBOX

2021 ◽  
Author(s):  
VINCENZO OLIVERI ◽  
GIOVANNI ZUCCO ◽  
MOHAMMAD ROUHI ◽  
ENZO COSENTINO ◽  
RONAN O’HIGGINS ◽  
...  
Keyword(s):  
Variable Stiffness ◽  
Thermoplastic Composite ◽  
High Fidelity ◽  
Material System ◽  
Load Carrying Capacity ◽  
Element Analysis ◽  
Single Piece ◽  
Load Carrying ◽  
Post Buckling ◽  
Composite Material System

The design of a multi-part aerospace structural component, such as a wingbox, is a challenging process because of the complexity arising from assembly and integration, and their associated limitations and considerations. In this study, a design process of a stiffeners-integrated variable stiffness three-bay wingbox is presented. The wingbox has been designed for a prescribed buckling and post-buckling performance (a prescribed real testing scenario) and made from thermoplastic composite material system (Carbon-PEEK) with the total length of three meters. The stiffeners and spars are integrated into the top and bottom panels of the wingbox resulting a single-piece blended structure with no fasteners or joints. The bottom skin also has an elliptical cut-out for access purposes. The composite tows are steered around this cutout for strain concentration reduction purposes. The fiber/tow steering in the top skin bays (compression side) has also been considered for improved compression-induced buckling load carrying capacity. The proposed design has been virtually verified via high fidelity finite element analysis.

scholarly journals The Assessment of Using CFRP to Enhance the Behavior of High Strength Reinforced Concrete Corbels

2021 ◽  
Vol 28 (1) ◽  
pp. 71-83
Author(s):  
Mazin Abdulrahman ◽  
Shakir Salih ◽  
Rusul Abduljabbar
Keyword(s):  
Reinforced Concrete ◽  
Ultimate Strength ◽  
Load Capacity ◽  
High Strength ◽  
Load Carrying Capacity ◽  
Test Results ◽  
Ultimate Load Capacity ◽  
Load Carrying ◽  
Externally Bonded ◽  
Effective Depth

In this research, an experimental study is conducted to investigate the behavior and strength of high strength reinforced concrete corbels externally bonded with CFRP fabric sheets and Plates with different patterns taking into account the effect of adopted variables in enhancing the ultimate strength; the effect of shear span to effective depth (a/d), configuration, type and amount of bonding. Eleven high strength reinforced corbels were cast and tested under vertical loads. Test results showed there was an improvement in the behavior and load carrying capacity of all strengthened corbels. An increasing in the ultimate strength of strengthened corbel by inclined CFRP strips reached to (92.1%) while the increasing reached to (84.21%) for using one horizontal CFRP Plates compared to un-strengthened reference specimen. Also, it can be conducted that the increase of (a/d) ratio from (0.6 to 0.8) resulted in decreasing by 21.05% in ultimate load capacity of corbels and from (0.4 to 0.6) by 31.25% and 58.69% in cracking and ultimate loads respectively Using CFRP .

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