Ultimate strain of stiffened steel box sections under bending moment and axial force fluctuations

Due to the advantage of saving indoor space, a special-shaped column frame attracted more attention of the engineers and researchers. This paper presented a quasi-static cyclic loading experiment of six specimens of reinforced concrete (RC) L-shaped columns under compression-flexure-shear-torsion combined loadings to investigate the effect in the ratio of torsion to moment (T/M) and axial compression ratio (n) on their seismic performance. The results showed that the failure modes of L-shaped specimens included bending failure, bending-torsion failure, and torsion-shear failure with the hysteretic curves exhibiting S shape. With the increase of T/M ratio, cracks on the flange developed more fully, and the height of plastic hinge decreased and torsion bearing capacity improved. Besides, as the T/M ratio increased the twist ductility increased, while displacement ductility decreased. On the other hand, with a higher axial compression ratio, torsion bearing capacity and bending stiffness were both increased. Moreover, the equivalent viscous damping coefficient of bending and torsion were 0.08~0.28 and 0.13~0.23, respectively. The average inter-story drift ratio met the requirements of the Chinese standard. Finally, two modified models were proposed to predict the progression of damage for the L-shaped column under combined loading including torsion.

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“…The Kumar model is the most widely used damage index for the RC column to quantify the damage as follows in Equation (5) [31][32][33].…”

Section: Flexural Damage Index Using the Kumar Approachmentioning

confidence: 99%

Experimental Study and Damage Model on the Seismic Behavior of Reinforced Concrete L-Shaped Columns under Combined Torsion

Yang²,

Chen

2020

Applied Sciences

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“…e study of nonlinear behavior of steel piers under bidirectional ground movement demonstrates the impact of radial and circumferential components on mechanical energy [5]. Other factors that affect the ductile behavior of steel piers include material and geometrical properties [6][7][8][9][10] and axial force fluctuations [11][12][13]. On the other hand, efforts have been also made to improve the ductile behavior.…”

Section: Introductionmentioning

confidence: 99%

Seismic Behavior of Box Steel Bridge Pier with Built-In Energy Dissipation Steel Plates

Han

Jiang²,

Zheng

et al. 2022

Advances in Materials Science and Engineering

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Based on the design concept of earthquake-resilient structure, a new-type of box-shaped steel piers with embedded energy-dissipating steel plates was proposed. Quasi-static tests of 6 box-shaped steel pier specimens under variable axial pressure and cyclic horizontal loading were carried out. By analyzing the failure mode, load-displacement hysteretic curve, skeleton curve, displacement ductility coefficient, stiffness degradation characteristics, strength degradation coefficient, and cumulative hysteretic energy, the effects of setting energy-dissipating steel plate, axial compression ratio, and thickness of energy dissipation steel plates on the seismic performance of new-type steel piers were discussed. Finite element models of steel bridge piers were established and compared with the test results. The analysis results using FEM agree well with the test results. Results show that the setting of energy-dissipating steel plates can effectively improve the ductility, deformation capacity, and energy-dissipating capacity of box-shaped steel piers, and effectively delay buckling deformation and cracking of wall plates. The steel plate near the bolt hole of the wall plate at the root of the new-type of box-shaped steel piers is easy to crack due to stress concentration, resulting in a rapid reduction of the maximum bearing capacity of the specimens. With the increase of axial compression ratio, the bearing capacity, energy-dissipating capacity, and earthquake-resilient capacity of the specimens increase. The smaller the thickness of the replaceable energy-dissipating steel plates, the smaller the bearing capacity and faster the stiffness degradation of the specimens become, while the ductility and energy-dissipating capacity of the specimens are improved. The axial compression ratio and the thickness of the energy-dissipating steel plate have relatively little effect on the strength degradation of the specimens. In order to facilitate the popularization and application of the new-type steel piers, formulas were also established to calculate the bearing capacity and displacement ductility factor of the new-type of box-shaped steel piers.

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Seismic behaviour of eccentrically compressed steel-box bridge-pier columns with embedded energy-dissipating shell plates

Cui

2020

Bull Earthquake Eng

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Ultimate strain of stiffened steel box sections under bending moment and axial force fluctuations

Cited by 7 publications

References 16 publications

Experimental Study and Damage Model on the Seismic Behavior of Reinforced Concrete L-Shaped Columns under Combined Torsion

Experimental Study and Damage Model on the Seismic Behavior of Reinforced Concrete L-Shaped Columns under Combined Torsion

Seismic Behavior of Box Steel Bridge Pier with Built-In Energy Dissipation Steel Plates

Seismic behaviour of eccentrically compressed steel-box bridge-pier columns with embedded energy-dissipating shell plates

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