scholarly journals Numerical Parametric Study of Fully Encased Composite Columns Subjected to Cyclic Loading

2022 ◽  
Vol 8 (1) ◽  
pp. 45-59
Author(s):  
Almoutaz Bellah Alsamawi ◽  
Nadir Boumechra ◽  
Karim Hamdaoui

This paper investigates the cyclic behaviour of steel-concrete encased composite columns. By investigating the cover concrete and the steel-concrete coefficient of friction on the behaviour (strength, ductility, stiffness, and energy dissipation) of composite columns subjected to combined axial load and cyclically increasing lateral load to improve the strength and performance of the composite column. Eight of the columns were designed to study the cover concrete effect, and eleven other columns were designed to study the coefficient of friction effect in the dynamic behaviour to the cyclic load. Additionally, in this study, the finite element models created in ANSYS software were verified and calibrated against previously published experimental results (load-displacement curve, load capacity and failure mode). The numerical results obtained from the finite element model indicate that the ductility and the energy dissipated increased by +11.71 and +18.93% receptively by the increase of the cover concrete until reaching the limit of the cover concrete. Beyond this limit, the ductility and the energy decrease by 27.33 and 24.97% receptively. The results also indicate that the ductility and the energy dissipated increased by 12.62 and 7.82% receptively by the increased coefficient of friction until reach 0.6, after that the energy decreases by 4.47%. Doi: 10.28991/CEJ-2022-08-01-04 Full Text: PDF

2015 ◽  
Vol 798 ◽  
pp. 53-58
Author(s):  
Salahaddin M. Sahboun ◽  
Simon M. Barrans

In this paper a finite element technique to predict the torsional load capacity of V-band clamp joints is presented. The development of this complex, multi-step analysis is explained and the results compared with alternate theories which ignore or take account of transverse friction in the band to flange contact region. It is shown that accounting for transverse friction yields a better comparison with the finite element results for lower coefficients of friction whilst ignoring this component gives better results for higher coefficients of friction. Torsional load capacity is shown to increase with band diameter and T-bolt tension but to be less dependent on the coefficient of friction.


2011 ◽  
Vol 255-260 ◽  
pp. 45-48 ◽  
Author(s):  
Ya Feng Xu ◽  
Xin Zhao ◽  
Yi Fu

Based on experimental research, the bearing performance of the new column (steel tube-reinforced concrete composite columns combination strengthened with angle steel and CFRP) has been studied in detail by finite element method. A finite element model is established based on a series of assumption. The load-displacement curves are obtained. The influence of steel ratio and thickness of CFRP layers to the bearing capacity is analyzed too. The result shows that both the steel ratio and the thickness of CFRP layers have great contribution to the axial load capacity. The finite element analysis results and theoretical analysis which are in good agreement show that simulation results are generally right.


2009 ◽  
Vol 416 ◽  
pp. 519-523
Author(s):  
Guo Zhi Zhang ◽  
Xian Hua Zhang ◽  
Li Li Liu ◽  
Zeng Ju Wei

Study on the effect of the surface manufacturing quality (roughness) to the friction between the surfaces. Based on the plastic theory of mechanism-based strain gradient (MSG) of the micro-plastic-mechanics and the contact theory, the theoretical model of the coefficient of friction between the rough surfaces and the non-linear finite element model between the grinding samples were established. Moreover, the surface stress distribution and the coefficient of friction were obtained through the sub-structure finite element method. The established model of static friction theoretical model and the accuracy of the finite element model were verified through comparing with the result of the static friction experiments between the grinding samples with different surface manufacturing quality. The study in the paper is important to the study on the surface friction mechanism.


Author(s):  
Yi Zhang ◽  
Wei Wang ◽  
Kun Liu ◽  
Baohong Tong ◽  
Zhaowen Hu ◽  
...  

High-strength boron steels are widely used in manufacturing the auto bodies and parts of light-weight vehicles, but the high rates of surface scratches and die wear have consistently occurred during hot stamping for these steels. For an in-depth understanding of the tribological characteristics at this interface, the frictional contact behavior and thermomechanical mechanisms of boron steel 22MnB5 against die steel H13 at 800 °C were studied through experiments and finite-element simulations. The coefficient of friction and worn surface topography were investigated by pin-on-disk sliding tests. A three-dimensional thermomechanical finite-element model of a friction pair was established to explore the interfacial dynamic variations. Experimental and simulation results show that severe elastic–plastic deformation occurred on the worn surface of the boron steel, whereas an increase in the load decreased the coefficient of friction within a certain range because the growth rate of shear force was slower than that of the normal force. When the finite-element model was changed from the gradual loading stage to the initial sliding stage, the tangential friction force further increased the plastic deformation on the surface of boron steel. The scratches and furrows were mainly caused by the compression and shear from asperities of the rough surface, as confirmed by the high-frictional-stress regions concentrated on the peaks and flanks of asperities. During the high-temperature and high-pressure experiments, the plasticized and softened surface materials of the boron steel adhered to the die surface readily, resulting in peeling and delamination.


2021 ◽  
Vol 15 (1) ◽  
pp. 7874-7884
Author(s):  
Aizat Alias ◽  
A.F.M. Amin

This paper presented a numerical investigation of a steel-concrete composite slab subjected to blast loads. The finite element model of the composite slab was developed and validated against experimental results. The validated finite element model of the composite slab then subjected to blast loads using CONWEP function in ABAQUS. A validation investigation was performed on CONWEP function by comparing the blast-pressure profiles from CONWEP against experimental data. Both validation studies showed that the developed finite element model of the composite slab and CONWEP agree reasonably well with test results. The fully restrained composite slab was subjected to four different blast loads with different explosive weights and standoff distances. The transient deformation of the composite slab after subjected to blast loads was investigated where as predicted the deformation of the composite slab was influenced by the blast pressure, which is affected by the weight of explosive and standoff distance. This study also investigated the mode of failure where it was determined flexural failure at the midspan is the main mode of failure accompanied with concrete tensile failure at the supports. The thickness of the profiled deck and the coeffecient of friction influenced the dynamic response of the composite slabs. Increasing the thickness reduces the maximum displacement of the composite slabs. Increasing the coefficient of friction reduces the maximum dislacement but once the coefficient of friction reach its optimum value, no positive benefit is gained.


1981 ◽  
Vol 103 (1) ◽  
pp. 73-82 ◽  
Author(s):  
H. Winter ◽  
H. Wilkesmann

The formulae of classical hydrodynamics are not suitable for the calculation of load capacity and power loss of worm gear drives. Thus a theoretical basis had to be developed for the comparison of different tooth profiles, materials of worm and worm wheel and lubricants. The data obtained were compared with test results. It proved that the coefficient of friction is an important influence factor.


2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Eden Shukri Kalib ◽  
Yohannes Werkina Shewalul

The responses of flat reinforced concrete (RC) floor slabs with openings subjected to horizontal in-plane cyclic loads in addition to vertical service loads were investigated using nonlinear finite element analysis (FEA). A finite element model (FEM) was designed to perform a parametric analysis. The effects of opening sizes (7%, 14%, 25%, and 30% of the total area of the slab), opening shapes (elliptical, circular, L-shaped, T-shaped, cross, and rectangular), and location on the hysteretic behavior of the floor slab were considered. The research indicated that openings in RC floor slabs reduce the energy absorption capacity and stiffness of the floor slab. The inclusion of 30% opening on the floor slab causes a 68.5%, 47.3%, and 45.6% drop in lateral load capacity, stiffness, and lateral displacement, respectively, compared to the floor slab with no openings. The flat RC floor slab with a circular opening shape has increased efficiency. The placement of the openings is more desirable by positioning the openings at the intersection of two-column strips.


Author(s):  
Andrei Costache ◽  
Christian Berggreen ◽  
Ion Marius Sivebæk ◽  
Kristian Glejbøl

Flexible risers are used in the offshore oil industry for exporting hydrocarbons from subsea equipment to floating production and storage vessels. The latest research in unbonded flexible pipes aims to reduce weight by replacing metal components with composite materials. This would result in lighter and stiffer flexible risers, which would be well suited for ultra deep water applications. This paper develops a new finite element model used for evaluating the efficiency of anchoring flat unidirectional fiber reinforced tendons in a mechanical grip. It consists two flat grips with the fiber reinforced tendon in between. The grips are pressed against the composite and the pullout force is ensured through friction. The novelty of the paper is represented by the detailed investigation of the influence between the coefficient of friction and the pullout force. By comparing numerical and experimentally obtained results, it is possible to show the importance of friction decay in the grip. Improper contact between the grips and composite is also taken into account and leads to good agreement between numerical and experimental results. This study shows how to avoid over-estimating the efficiency of such grip by using dry friction in finite element models.


2010 ◽  
Vol 44-47 ◽  
pp. 2931-2934
Author(s):  
Chun Ling Wu ◽  
Bang Yan Ye

Ultra-fine grained chips with higher hardness and strength than bulk can be produced by severe plastic deformation during orthogonal metal cutting. A finite element method was developed to characterize the distribution of stress, strain, strain rate and temperature in the deformation area at different rake angles and cutting velocities. The coefficient of friction in the tool-chip interface is approximately obtained according model of mean coefficient of friction which is based on experiments in any machining conditions. The formation mechanics of ultra-fine grained chip is discussed and effect of rake angle on microstructure of chips is highlighted. The results of experiment and modeling have shown that chip materials with ultra-fine grained and high hardness can be produced with more negative tool rake angle at some lower cutting velocity.


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