scholarly journals Finite Element Analysis of Cracked One-Way Bubbled Slabs Strengthened By External Prestressed Strands

2021 ◽  
Vol 27 (1) ◽  
pp. 45-65
Author(s):  
Falah Hassan Ibrahim ◽  
Ali Hussein Ali
Keyword(s):  
Ultimate Load ◽  
Load Capacity ◽  
The Other ◽  
Ultimate Load Capacity ◽  
Element Analysis ◽  
Line Load ◽  
External Prestressing ◽  
Service Charge ◽  
External Strengthening ◽  
Initial Capacity

Bubbled slabs can be exposed to damage or deterioration during its life. Therefore, the solution for strengthening must be provided. For the simulation of this case, the analysis of finite elements was carried out using ABAQUS 2017 software on six simply supported specimens, during which five are voided with 88 bubbles, and the other is solid. The slab specimens with symmetric boundary conditions were of dimensions 3200/570/150 mm. The solid slab and one bubbled slab are deemed references. Each of the other slabs was exposed to; (1) service charge, then unloaded (2) external prestressing and (3) loading to collapse under two line load. The external strengthening was applied using prestressed wire with four approaches, which are L1-E, L2-E, L1-E2, and L2-E2, where the lengths and eccentricities of prestressed wire are (L1=1800, L2=2400, E1=120 and E2=150 mm). The results showed that each reinforcement approach restores the initial capacity of the bubbled slab and improves it in the ultimate load capacity aspect. The minimum and maximum ultimate strength of strengthened cracked bubbled slab increased by (17.3%-64.5%) and (25.7%-76.3%) than solid and bubbled slab, respectively. It is easier to improve behavior with an increased eccentricity of the prestressed wire than to increase its length.

scholarly journals Finite Element Analysis of Cracked One-Way Bubbled Slabs Strengthened By External Prestressed Strands

2021 ◽  
Vol 27 (1) ◽  
pp. 45-65
Author(s):  
Falah Hassan Ibrahim ◽  
Ali Hussein Ali
Keyword(s):  
Ultimate Load ◽  
Load Capacity ◽  
The Other ◽  
Ultimate Load Capacity ◽  
Element Analysis ◽  
Line Load ◽  
External Prestressing ◽  
Service Charge ◽  
External Strengthening ◽  
Initial Capacity

Bubbled slabs can be exposed to damage or deterioration during its life. Therefore, the solution for strengthening must be provided. For the simulation of this case, the analysis of finite elements was carried out using ABAQUS 2017 software on six simply supported specimens, during which five are voided with 88 bubbles, and the other is solid. The slab specimens with symmetric boundary conditions were of dimensions 3200/570/150 mm. The solid slab and one bubbled slab are deemed references. Each of the other slabs was exposed to; (1) service charge, then unloaded (2) external prestressing and (3) loading to collapse under two line load. The external strengthening was applied using prestressed wire with four approaches, which are L1-E, L2-E, L1-E2, and L2-E2, where the lengths and eccentricities of prestressed wire are (L1=1800, L2=2400, E1=120 and E2=150 mm). The results showed that each reinforcement approach restores the initial capacity of the bubbled slab and improves it in the ultimate load capacity aspect. The minimum and maximum ultimate strength of strengthened cracked bubbled slab increased by (17.3%-64.5%) and (25.7%-76.3%) than solid and bubbled slab, respectively. It is easier to improve behavior with an increased eccentricity of the prestressed wire than to increase its length.

scholarly journals The Behavior of a Strengthened Steel Beam Section Under Eccentric Loadings

2021 ◽  
Vol 318 ◽  
pp. 03007
Author(s):  
Mohammed M. Rasheed ◽  
Kamal Sh. Mahmoud ◽  
Saad Khalaf Mohaisen ◽  
Mohammed Z. Yousif
Keyword(s):  
Ultimate Load ◽  
Load Capacity ◽  
The Other ◽  
Steel Beams ◽  
Steel Beam ◽  
Ultimate Load Capacity ◽  
Cross Sectional ◽  
External Prestressing ◽  
Beam Section ◽  
Prestressing Strand

Thirteen simply supported steel samples have been tested to explain the effects of strengthening steel beams using an external prestressing strand. The samples have the same cross-sectional dimensions and overall length. One steel beam without strengthening was taken as a reference, while the other twelve of them had been strengthening by two external strands at various eccentricity locations and jacking stresses. The strengthening by external prestressing strands is sub-divided into two series according to jacking stress. Each series consists of six steel samples divided according to the eccentricity location of prestressing strand. During tests, it was found that the Load deflection response for the strengthened samples is stiffer as compared with the reference. The increasing percentage in ultimate load capacity was increased to 0.347, 2.758, 3.921, 8.898, 9.326, and 10.256% for beams under jacking stress of 1120 MPa, while increasing percentage in ultimate load capacity were increased to 0.17, 26, 33, 48.5, 13.7, and 69.56% for beams under jacking stress of 815 MPa. On the other hand, the maximum percentages of deflection were decreased to 4.88, 2.44, 20.62, 15, and 9.7% when the jacking stress increase from 815 to 1120 MPa and the ratio of the quarter to mid-span deflection (δ quarter / δ mid) is about 0.528 and 0.497 when jacking stress is 1120 and 815 MPa respectively. So, the increase in jacking stresses from 815 to 1120 MPa will not be preferable because it has a little increasing percentage in stiffening and behaviors compared with other tested beams at the same condition.

scholarly journals An innovation for flat traditional conventional footing

2021 ◽  
Vol 23 (07) ◽  
pp. 358-364
Author(s):  
Aakriti Sharma ◽  
◽  
Dr. Prashant Garg ◽  
Amandeep Singh ◽  
◽  
...  
Keyword(s):  
Ultimate Load ◽  
Load Capacity ◽  
Experimental Studies ◽  
Failure Surface ◽  
Good Method ◽  
Test Results ◽  
Ultimate Load Capacity ◽  
Element Analysis ◽  
Shell Foundation ◽  
Shell Foundations

Since their inception in the 1950s, shell foundations have grown in popularity over regular ones. In this paper, the ultimate load capacities of shell foundations on clay were determined by Numerical model tests. The results were compared with those for flat foundations with the same base. The model test results were found using finite element analysis using the program PLAXIS 2D. The experimental studies indicated that the ultimate load capacity of shell footing on clay is higher than that on flat-footing and the load settlement curves were significantly modified. The shell foundation over clay can be considered a good method to decrease the resulting settlement and material consumption at different thicknesses. Also, the rupture surface of the shell upright and inverted system was significantly deeper than both normal footings. The numerical analysis helps in understanding the deformation behavior of the studied systems and identifies the failure surface of upright and inverted shell footing.

Discussion of “Ultimate Load Capacity of Arch Dams”

1967 ◽  
Vol 93 (3) ◽  
pp. 259-267
Author(s):  
Marek Janas ◽  
Lance A. Endersbee ◽  
M.L. Juncosa ◽  
K.V. Swaminathan ◽  
A. Rajaraman
Keyword(s):  
Ultimate Load ◽  
Load Capacity ◽  
Ultimate Load Capacity ◽  
Arch Dams

Performance of Reinforced Concrete Beams with Multiple Openings

2020 ◽  
Vol 857 ◽  
pp. 162-168
Author(s):  
Haidar Abdul Wahid Khalaf ◽  
Amer Farouk Izzet
Keyword(s):  
Reinforced Concrete ◽  
Ultimate Load ◽  
Concrete Beams ◽  
Load Capacity ◽  
Reinforced Concrete Beams ◽  
Design Parameters ◽  
Ultimate Load Capacity ◽  
Concentrated Load ◽  
Simply Supported ◽  
Group I

The present investigation focuses on the response of simply supported reinforced concrete rectangular-section beams with multiple openings of different sizes, numbers, and geometrical configurations. The advantages of the reinforcement concrete beams with multiple opening are mainly, practical benefit including decreasing the floor heights due to passage of the utilities through the beam rather than the passage beneath it, and constructional benefit that includes the reduction of the self-weight of structure resulting due to the reduction of the dead load that achieves economic design. To optimize beam self-weight with its ultimate resistance capacity, ten reinforced concrete beams having a length, width, and depth of 2700, 100, and 400 mm, respectively were fabricated and tested as simply supported beams under one incremental concentrated load at mid-span until failure. The design parameters were the configuration and size of openings. Three main groups categorized experimental beams comprise the same area of openings and steel reinforcement details but differ in configurations. Three different shapes of openings were considered, mainly, rectangular, parallelogram, and circular. The experimental results indicate that, the beams with circular openings more efficient than the other configurations in ultimate load capacity and beams stiffness whereas, the beams with parallelogram openings were better than the beams with rectangular openings. Commonly, it was observed that the reduction in ultimate load capacity, for beams of group I, II, and III compared to the reference solid beam ranged between (75 to 93%), (65 to 93%), and (70 to 79%) respectively.

scholarly journals Experimental Study on the Effect of Heel Plate Length on the Structural Integrity of Cold-formed Steel Roof Trusses

2018 ◽  
Vol 65 ◽  
pp. 08010
Author(s):  
Je Chenn Gan ◽  
Jee Hock Lim ◽  
Siong Kang Lim ◽  
Horng Sheng Lin
Keyword(s):  
Ultimate Load ◽  
Structural Integrity ◽  
Load Capacity ◽  
Local Buckling ◽  
Ultimate Capacity ◽  
Ultimate Load Capacity ◽  
Plate Length ◽  
Roof Truss ◽  
Cold Formed Steel ◽  
Structural Failures

Applications of Cold-Formed Steel (CFS) are widely used in buildings, machinery and etc. Many researchers began the research of CFS as a roof truss system. It is required to increase the knowledge of the configurations of CFS roof trusses due to the uncertainty of the structural failures regarding the materials and rigidity of joints. The objective of this research is to investigate the effect of heel plate length to the ultimate load capacity of CFS roof truss system. Three different lengths of heel plate specimens were fabricated and subjected to concentrated loads until failure. The highest ultimate capacity for the experiment was 30 kN. The results showed that the increment of the length of the heel plate had slightly increased the ultimate capacity and strain. The increment of the length of the heel plate had increased the deflection of the bottom chords but decreased the deflection of the top chords. Local buckling of top chords adjacent to the heel plate was the primary failure mode for all the heel plate specimens.

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