Flexural capacity and bending stiffness of welded hollow spherical joints with H-beams

2020 ◽  
pp. 136943322097173
Author(s):  
Xiangyu Yan ◽  
Yuxuan Zhang ◽  
Zhihua Chen ◽  
Hongbo Liu ◽  
Qiwu Zhang
Keyword(s):  
Wall Thickness ◽  
Failure Modes ◽  
Bending Stiffness ◽  
Tensile Fracture ◽  
Flexural Capacity ◽  
Pure Bending ◽  
Welding Seam ◽  
Structural Calculation ◽  
H Beam ◽  
Parametric Analyses

Eight specimens were designed, and pure bending tests were completed to study the mechanical properties of welded hollow spherical joints (WHS joints) with an H-beam subjected to pure bending. Parametric analyses of the joints under pure bending were conducted in consideration of the diameter(D) and wall thickness (t) of the welded hollow sphere(WHS), and height (h) and width (b) of the H-beam to validate the numerical model. Calculation methods for the flexural capacity and bending stiffness of the H-beam WHS joints were proposed. Results revealed two failure modes of the joints under pure bending, namely, (1) concave at the connection between the WHS and upper flange and external heave at the connection between the WHS and lower flange and (2) small concave at the connection between the WHS and upper flange and tensile fracture of the welding seam at the connection between the WHS and lower flange. The joints demonstrated good ductility under pure bending. The flexural capacity and bending stiffness of the joints were positively related to the wall thickness of the WHS and to the height and width of H-beam but were negatively correlated with the diameter of the WHS. The errors between proposed formulas and FEA for calculating flexural capacity and bending stiffness are very small, indicating the formulas can be employed in structural calculation instead of FEA.

Experimental and Numerical Studies on Flexural Behavior of Casing Joint of Square Steel Tube

2010 ◽  
Vol 163-167 ◽  
pp. 417-420
Author(s):  
Min Ding ◽  
Zhen Hua Hou ◽  
Xiu Gen Jiang ◽  
Yu Zhi He ◽  
Guang Kui Zhang ◽  
...  
Keyword(s):  
Wall Thickness ◽  
Failure Modes ◽  
Shear Failure ◽  
Tube Wall ◽  
Edge Length ◽  
Steel Tube ◽  
Flexural Behavior ◽  
Flexural Capacity ◽  
Tube Wall Thickness ◽  
Square Steel Tube

The tests on thirteen specimens of casing joints of square steel tube were conducted to investigate the flexural behavior of the joints. And numerical simulation studies on that were carried out by ANSYS/LS-DYNA. On this basis, effects of tube wall thickness, tube edge length, and inserting depth on failure mode, ultimate flexural capacity and deformation of the joints were discussed. The results show that there are two types of failure modes, i.e., inside tube yield failure and outside tube shear failure. Ultimate flexural capacity and rigidity of the joints increased with the inserting depth increasing. The ultimate flexural capacity is proportional to tube shear strength, tube wall thickness, inserting depth, and tube edge length.

scholarly journals Comparison of bending stiffness of six different colours of copolymer polypropylene

1999 ◽  
Vol 23 (1) ◽  
pp. 63-71 ◽  
Author(s):  
R. S. Ross ◽  
R. J. Greig ◽  
P. Convery
Keyword(s):  
Electron Microscope ◽  
Wall Thickness ◽  
Modulus Of Elasticity ◽  
Microscope Study ◽  
Electron Microscope Study ◽  
Bending Moment ◽  
Bending Stiffness ◽  
Ankle Foot Orthosis ◽  
Uniform Wall ◽  
Foot Orthosis

This paper compares the bending stiffness of 5 different colours of copolymer polypropylene (CCP) with that of natural copolymer polypropylene (NCP). Flesh coloured and natural sheets are supplied thicker than other pigmented sheet. The bending stiffness of a specimen may be defined as EI, i.e. the product of E, Young's modulus of elasticity and I, the 2nd moment of area. Strips of “as supplied” (AS) and “post-draped” (PD) specimen were clamped and subjected to bending to assess the effect of pigmentation on bending characteristics. The gradient of the graph of bending deflection δ versus bending moment enables EI to be estimated. The process of thermoforming polypropylene reduces EI, the bending stiffness. However, the manual draping and vacuum procedure introduces so many variables that it is difficult to quantify the effect of pigmentation. The E of a bent specimen may be estimated from the gradient of the graph of δI versus bending moment. In the case of AS sheet, the effect of pigmentation on E is inconclusive. PD specimens indicate a significant reduction in E due to thermoforming. This was verified by an electron-microscope study of AS and PD specimens. Draping an ankle-foot orthosis (AFO) results in a non-uniform wall thickness. The results of this study with respect to the effects of pigmentation on the bending stiffness of AFOs are inconclusive. More detailed studies require to be completed in order to confirm which factors are responsible for this non-uniformity in wall thickness and consequent variation in bending stiffness.

scholarly journals Investigation of Slip Occurrence in the Ring Rolling Process

2019 ◽  
Vol 291 ◽  
pp. 02006
Author(s):  
Andrzej Gontarz ◽  
Piotr Surdacki
Keyword(s):  
Wall Thickness ◽  
Failure Modes ◽  
Rolling Process ◽  
Ring Rolling ◽  
Thickness Reduction ◽  
Main Stage ◽  
Forming Process ◽  
Limit Values ◽  
Ring Shape ◽  
Ring Rolling Process

Ring rolling is a hot forming process for producing rings that have large diameters when compared to their cross sections. This process is very dynamic and involves considerable variations in ring shape and size. One of the failure modes in ring rolling processes is slip that occurs when a thickness reduction, exceeds the limit value. The thickness reduction depends on the tool speed and dimensions as well as ring size, and varies over time. This paper reports results of a study investigating the thickness reduction with respect to slip occurrence. In terms of wall thickness reduction, the process can be divided into three distinct stages (excluding the sizing stage): (i) initial stage corresponding to the first revolution of the roll, (ii) main stage, when the proper ring rolling takes place, (iii) final stage, when the main roll does not move in an axial direction but the ring is being formed during one revolution of the tool. It has been found that the most slip-prone moment is the end of the second and the beginning of the third stage of the ring rolling process, when the wall thickness reduction is the highest. Based on a comparison of the calculated thickness reduction and its limit values, it could be predicted whether slip would occur, and if so – in what stage of the rolling process. Numerical results and experimental findings are in good agreement.

Analysis on Flexural Capacity of FRP Reinforced Concrete Members

2012 ◽  
Vol 446-449 ◽  
pp. 98-101
Author(s):  
Chun Xia Li ◽  
Zhi Sheng Ding ◽  
Shi Lin Yan
Keyword(s):  
Reinforced Concrete ◽  
Material Properties ◽  
Failure Modes ◽  
Reinforcement Ratio ◽  
Flexural Capacity ◽  
Steel Reinforced Concrete ◽  
Concrete Members

The balanced reinforcement ratio of FRP-reinforced concrete members and the flexural capacity under two different failure modes (concrete crushing and FRP rupture) are established, based on the analysis on flexural capacity of steel-reinforced concrete members in current concrete code. The effect of material properties on the balanced ratio, the variation of flexural capacity with different reinforcement ratio and a simplified nominal flexural capacity under FRP-rupture failure are derived.

Failure Modes of a Laminated Composite With Complaint Interlayers

2020 ◽  
Vol 88 (3) ◽  
Author(s):  
M. R. O’Masta ◽  
V. S. Deshpande
Keyword(s):  
Failure Mechanism ◽  
Failure Mode ◽  
Failure Modes ◽  
Volume Fraction ◽  
Flexural Rigidity ◽  
Laminated Composite ◽  
High Volume ◽  
Tensile Fracture ◽  
Reduced Order ◽  
Fe Simulations

Abstract Composites comprising a high-volume fraction of stiff reinforcements within a compliant matrix are commonly found in natural materials. The disparate properties of the constituent materials endow resilience to the composite, and here we report an investigation into some of the mechanisms at play. We report experiments and simulations of a prototype laminated composite system comprising silicon layers separated by polymer interlayers, where the only failure mechanism is the tensile fracture of the brittle silicon. Two failure modes are observed for such composites loaded in three-point bending: failure under the central roller in (i) the top ply (in contact with the roller) or (ii) the bottom ply (free surface). The former mode is benign with the beam retaining load carrying capacity, whereas the latter leads to catastrophic beam failure. Finite element (FE) simulations confirm this transition in failure mode and inform the development of a reduced order model. Good agreement is shown between measurements, FE simulations, and reduced order predictions, capturing the effects of material and geometric properties on the flexural rigidity, first ply failure mode, and failure load. A failure mechanism map for this system is reported that can be used to inform the design of such laminated composites.

Experimental Investigation on Bending Performance of Steel-Concrete Composite Slim Beams

2020 ◽  
Vol 853 ◽  
pp. 182-186
Author(s):  
Yu Chen Jiang ◽  
Xia Min Hu ◽  
Huai Dong Yan
Keyword(s):  
Experimental Investigation ◽  
Bending Stiffness ◽  
Steel Beams ◽  
Test Results ◽  
Flexural Capacity ◽  
Relative Slip ◽  
Bending Performance ◽  
Deformation Ability ◽  
Composite Slim Beam ◽  
Considerable Deformation

In this paper, the mechanical behavior of steel-concrete composite slim beams was investigated by experiments, and the influence of sectional dimension of steel beams on the bending stiffness and flexural capacity of composite slim beams was evaluated. Test results show that good cooperative performance can be achieved in steel-concrete composite slim beams and the relative slip between steel and concrete is very small. The steel-concrete slim beam presents considerable deformation ability beyond the service stage, which indicates that the composite slim beam has good ductility. In addition, sectional dimension of steel beams is proved to have significant influence on both the bending stiffness and flexural capacity of composite slim beams.

FE Modeling of Elliptical Concrete-Filled Steel Tubular Members Subjected to Pure Bending

2013 ◽  
Vol 859 ◽  
pp. 105-108
Author(s):  
Xiong Zhao ◽  
Xu Kuan Li ◽  
Qing Xin Ren ◽  
Tai Cheng ◽  
Xiao Lian Long
Keyword(s):  
Failure Modes ◽  
Steel Tube ◽  
Fe Model ◽  
Stress Distributions ◽  
Fe Modeling ◽  
Pure Bending ◽  
Element Analysis ◽  
Elliptical Section ◽  
As Stress ◽  
Good Agreement

This paper reports a finite element analysis of the flexural behaviour of concrete-filled steel tubular members with elliptical section. A set of test data were used to verify the FE modeling. generally, good agreement was achieved. Typical curves of moment (M) versus deflection at mid-span (um), as well as stress distributions of steel tube and concrete of the composite members were compared and discussed. The results clearly show that the FE model is available for predicting the load-bearing capacities and the failure modes of the specimens.

Flexural Fracture and Fatigue Behavior of RC Beams Strengthened with CFRP Laminates under Constant Amplitude Loading

2006 ◽  
Vol 306-308 ◽  
pp. 1343-1348 ◽  
Author(s):  
Guowen Yao ◽  
Pei Yan Huang ◽  
Chen Zhao
Keyword(s):  
Fatigue Damage ◽  
Failure Modes ◽  
Fatigue Behavior ◽  
Bending Stiffness ◽  
Rc Beam ◽  
Rc Beams ◽  
Constant Amplitude ◽  
Damage State ◽  
Engineering Structures ◽  
Damage And Fracture

Externally bonded carbon fiber reinforced polymer (CFRP) materials are well suited to the rehabilitation and reinforcement of civil engineering structures due to their high specific strength, specific stiffness and corrosion resistance. To probe the fatigue behavior of CFRP strengthened concrete structures, three point bending experiments of reinforced concrete (RC) beams strengthened with carbon fibre laminate (CFL) under constant amplitude loading were performed. The histories of midspan flexibility and bending stiffness of strengthened beams were recorded automatically. And the linear curve between fatigue strength and the logarithm of fatigue life was obtained. The failure modes go through concrete cracking, CFL debonding from concrete and steel bars yielding and fracture with increasing cycles of fatigue loading. Bonded CFL increases the ductility of strengthened RC beam and results in dense distribution of cracks compared with normal RC beam, and it’s bending stiffness at damage state as well. The fatigue damage evolvement shows three stages of nucleation, steady expansion and failure. Then the failure mechanism was studied and a cumulative damage model was proposed to describe the fatigue damage and fracture process of CFL strengthened RC beams under constant amplitude loading.

scholarly journals Mechanical properties and progressive failure characteristics of sandstone containing elliptical and square openings subjected to biaxial stress

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0246815
Author(s):  
Honggang Zhao ◽  
Haitao Sun ◽  
Dongming Zhang ◽  
Chao Liu
Keyword(s):  
Mechanical Properties ◽  
Failure Mode ◽  
Failure Modes ◽  
Biaxial Stress ◽  
Tensile Fracture ◽  
Biaxial Compression ◽  
Lateral Stress ◽  
Variable Theory ◽  
Failure Characteristics ◽  
Elliptical Opening

Two kinds of common tunnel shapes, i.e. elliptical opening and square opening were selected for biaxial compression tests, and the influences of two kinds of opening shapes on the mechanical properties, failure characteristics and failure modes of sandstone were compared and analyzed. The complex variable theory and mapping functions were used to obtain the analytical stress solution around elliptical and square openings. The results show that the stability of the specimen containing an elliptical opening was better than that of the specimen containing a square opening under the same lateral stress. Compared with the elliptical opening, the local damage was formed earlier in the square opening which might be caused by a higher stress concentration around the square opening. The stress distributions around openings were influenced by the opening shape and lateral stress coefficient. The top and bottom of square opening were more prone to tensile fracture, and the distribution range of tensile was larger than that of elliptical opening. When the opening failed, the intensity of square opening failure was weaker than that of elliptical opening. On the basis of the average frequency value and the rise angle value, the failure mode of specimen containing elliptical or square opening was distinguished. It was found that the mixed tension and shear failure dominated the failure of specimens with different opening shapes, and the number of shear cracks in the specimen containing a square opening was greater than that in the specimen containing an elliptical opening. The above method of judging failure mode by acoustic emission signals was well verified by the CT images of damaged specimens.

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