Formulation of the quantitative influence of local and overall initial deflections on load-bearing capacity of unstiffened welded square box section columns under axial compression

The section of steel column under axial compression presents heterogeneous material and its load condition changes after experiencing fire damage of one side. Taking H-section steel column under axial compression commonly used in engineering for study object in this thesis in order to study post-fire residual load bearing capacity, the post-fire eccentric effect of steel column under axial compression exposure to one-side fire is analyzed using the method of equivalent section which considering the change of the material strength after high temperature, the influence of non-uniform temperature field on material properties and the stiffness degradation of member section. Calculation methods of the eccentricity and additional moment are proposed and further given a formula of residual load bearing capacity.

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An experimental study of the axial compression performance of two-part precast concrete columns

Advances in Structural Engineering ◽

10.1177/13694332211015923 ◽

2021 ◽

pp. 136943322110159

Author(s):

Bo Wu ◽

Zhikai Wei

Keyword(s):

Bearing Capacity ◽

Axial Compression ◽

Axial Load ◽

Precast Concrete ◽

Concrete Columns ◽

Longitudinal Reinforcement ◽

Load Bearing Capacity ◽

Load Bearing ◽

Compression Performance ◽

Waste Concrete

Recycled lump concrete (RLC) made with demolished concrete lumps (DCLs) and fresh concrete (FC) provides a solution for effective waste concrete recycling. To promote the development of precast RLC structures, this study tested a new type of connection for precast concrete columns: connecting the upper and the lower halves of columns with bent longitudinal reinforcements and structural adhesive. In this work the behavior of precast RLC columns with the new connection was studied under axial compression. The axial compressive strength of nine two-part columns was tested. The effects of the degree of bending in the longitudinal reinforcement, the replacement ratio of DCLs and the stirrup spacing were investigated. Tests showed that: (1) the failure mode of precast concrete columns is different from that of cast-in-place columns; (2) when the strength of the waste concrete is close to that of the fresh material, there is no significant difference in the axial compression performance of either precast or cast-in-place columns; (3) the bent longitudinal reinforcement causes the axial load bearing capacity of precast concrete columns to be 4.2%–12.3% lower than that of a similar cast-in-place column; (4) reducing the stirrup spacing has little effect on a precast column’s axial load bearing capacity and ductility; (5) when using Chinese and American codes to predict the axial load bearing capacity of the column, the predicted value should be multiplied by a reduction factor.

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Experimental and Numerical Investigation of the Fracture Behavior of Welded Aluminum Cross Joints under Axial Compression

Materials ◽

10.3390/ma13194310 ◽

2020 ◽

Vol 13 (19) ◽

pp. 4310

Author(s):

Hannes Panwitt ◽

Horst Heyer ◽

Manuela Sander

Keyword(s):

Numerical Simulations ◽

Bearing Capacity ◽

Axial Compression ◽

Fracture Behavior ◽

Stress Triaxiality ◽

Base Material ◽

Compression Tests ◽

Load Bearing Capacity ◽

Load Bearing ◽

Welded Structure

In age-hardened high-strength aluminum alloys, the area with and around a joint has a large impact on the load-bearing capacity of a welded structure. Therefore, in this study the fracture behavior of welded EN AW 6082 T6 plates is investigated experimentally and numerically. From butt joints, smooth and notched tensile specimens as well as shear specimens have been manufactured and tested for the base material (BM), heat-affected zone (HAZ) and fusion zone (FZ). With numerical simulations of these tests, the dependency of the fracture strain on the stress triaxiality is determined, and two phenomenological fracture criteria are calibrated. Whereas the one-parameter Rice–Tracey/Cockcroft–Latham (RTCL) criterion describes the behavior of the tension specimens as accurately as the two-parameter Bao–Wierzbicki (BW) criterion, the BW criterion is more accurate for shear tests. Subsequently, the material model is validated on axial compression tests of welded X-profiles. The experiments comprise tests with different plate thicknesses (8 mm, 10 mm and 12 mm) and varying strain rates (up to 1/s locally), showing the same behavior for all specimens. After crack initiation within the FZ, coalescence of cracks leads to crack growth in axial direction and a subsequent reduction of the load-bearing capacity. This behavior is reproduced well by the numerical simulations with the BW criterion, whereas simulations with the RTCL criterion predict fracture initiation at too high displacements. Overall, the results show the strong influence of the ductility of the FZ on the crushing behavior of welded X-profiles.

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INFLUENCE OF INITIAL DEFLECTIONS ON COUPLED BUCKLING STRENGTH OF UNSTIFFENED SQUARE BOX SECTION COLUMNS

Proceedings of International Structural Engineering and Construction ◽

10.14455/isec.res.2018.105 ◽

2018 ◽

Vol 5 (2) ◽

Author(s):

Xiang Chen ◽

Shozo Nakamura ◽

Toshihiro Okumatsu ◽

Takafumi Nishikawa

Keyword(s):

Bearing Capacity ◽

Slenderness Ratio ◽

Thickness Ratio ◽

Initial Deflection ◽

Influence Coefficient ◽

Load Bearing Capacity ◽

Load Bearing ◽

Buckling Strength ◽

Maximum Decrease ◽

Quantitative Influence

Although it is well known that initial deflections have a significant influence on coupled buckling strength, their quantitative influence is not clear. In this paper, a series of nonlinear finite element analyses to reveal the quantitative influence of initial deflections on coupled buckling strength are conducted with MSC.Marc. There are nine kinds of combinations about the size of local and overall initial deflections including 1/75, 1/150, 1/450 of the plate width and 1/500, 1/1000, 1/3000 of the column length. In addition, the width-thickness ratio and slenderness ratio parameters are also varied in the parametrical study. Both ranges of slenderness and the width-thickness ratio parameters are from 0.1 to 2.1. As a result, the initial deflection influence coefficient is proposed to describe the quantitative influence of local and overall initial deflections on coupled buckling strength. The numerical results reveal that the coefficient decreases with the increase of initial deflections. The sensitivity of the strength to initial deflections depends on both width-thickness and slenderness ratio parameters. The maximum decrease of 21.4% on load-bearing capacity caused by local initial deflection appears when width-thickness and slenderness ratio parameters equal to 1.2 and 2.1, respectively. Column strength is quite sensitive to overall initial deflection at the slenderness ratio parameter equal to 1.4. The maximum decrease in load-bearing capacity reaches 18.2%.

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Experimental Research on Behavior of CFRP Circular Steel Tubular Confined Recycled Aggregate Concrete Columns under Axial Compression

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.744-746.96 ◽

2015 ◽

Vol 744-746 ◽

pp. 96-99

Author(s):

Jiong Feng Liang ◽

Ze Ping Yang ◽

Ming Hua Hu

Keyword(s):

Bearing Capacity ◽

Axial Compression ◽

Concrete Columns ◽

Recycled Aggregate Concrete ◽

Recycled Aggregate ◽

Compression Tests ◽

Load Bearing Capacity ◽

Aggregate Concrete ◽

Load Bearing ◽

Cfrp Wrapping

In order to further promote the use of recycled aggregate concrete in practice, axial compression tests were carried out for 7 CFRP circular steel tubular confined recycled aggregate concrete columns. The influence of the replace rate of recycled aggregate concrete, the wrapping method on axial compression behavior of CFRP circular steel tubular confined recycled aggregate concrete columns were analyzed. Based on the results of the tests, with the replace rate of recycled aggregate concrete increasing, the specimens have an decreasing trend in the load bearing capacity. The whole CFRP wrapping circular steel tubular confined recycled aggregate concrete columns have higher load bearing capacity than the three stripe wrapping ones.

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Increased load bearing capacity of mechanically joined FRP/metal joints using a pin structured auxiliary joining element

Materials Testing ◽

10.3139/120.111453 ◽

2020 ◽

Vol 62 (1) ◽

pp. 55-60

Author(s):

Per Heyser ◽

Vadim Sartisson ◽

Gerson Meschut ◽

Marcel Droß ◽

Klaus Dröder

Keyword(s):

Bearing Capacity ◽

Load Bearing Capacity ◽

Load Bearing

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Load-Bearing Capacity of Direct Inlay-Retained Fibre-reinforced Composite Fixed Partial Dentures with Different Cross-Sectional Pontic Design

Revista de Chimie ◽

10.37358/rc.17.1.5397 ◽

2017 ◽

Vol 68 (1) ◽

pp. 94-100

Author(s):

Oana Tanculescu ◽

Adrian Doloca ◽

Raluca Maria Vieriu ◽

Florentina Mocanu ◽

Gabriela Ifteni ◽

...

Keyword(s):

Bearing Capacity ◽

Fracture Pattern ◽

Load Bearing Capacity ◽

Cross Sectional ◽

Load Bearing ◽

Reinforced Composite ◽

Polyethylene Fibre

The load-bearing capacity and fracture pattern of direct inlay-retained FRC FDPs with two different cross-sectional designs of the ponticwere tested. The aim of the study was to evaluate a new fibre disposition. Two types of composites, Filtek Bulk Fill Posterior Restorative and Filtek Z250 (3M/ESPE, St. Paul, MN, USA), and one braided polyethylene fibre, Construct (Kerr, USA) were used. The results of the study suggested that the new tested disposition of the fibres prevented in some extend the delamination of the composite on buccal and facial sides of the pontic and increased the load-bearing capacity of the bridges.

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