scholarly journals Mechanical Performance Study of Tower Crane Braced Frame Joint with Different Embedded Part Parameters

2019 ◽  
Vol 2019 ◽  
pp. 1-14
Author(s):  
Yao Gang ◽  
Yang Yang ◽  
Liao Gang ◽  
Huang Zulin ◽  
Weng Bangzheng
Keyword(s):  
Finite Element ◽  
Bearing Capacity ◽  
Failure Mechanism ◽  
Failure Mode ◽  
Mechanical Performance ◽  
Ultimate Bearing Capacity ◽  
Braced Frame ◽  
Research Results ◽  
Tower Crane ◽  
Anchor Length

Embedded part has significant effects on the mechanical performance of tower crane braced frame joint. In this study, a series of experiments with different embedded part parameters are conducted on ultimate bearing capacity, load-displacement relationship, load-strain relationship, failure mode, and failure mechanism. Finite element models are established by the ABAQUS software and compared with the experiment results to verify rationality and credibility of the models. The present experimental study and finite element model analysis focus on the effects of anchor length, anchor width, and endplate area. The research results show that embedded part is pulled out of braced frame joint without plastic deformation, and local stress distribution of braced frame joint is complex with tension, bending, and shear load. The braced frame joint is severely strained and cracked with ultimate bearing capacity. Influence of embedded part parameters on mechanical performance of braced frame joint decreases in the order of anchor length, endplate area, and anchor width. The embedded part parameters have no influence on failure mode but affect the failure mechanism. Ultimate bearing capacity of embedded part is about four times the cracking bearing capacity, and an effective approach to improve ultimate bearing capacity is increasing anchor length. The research results can provide a better understanding of the sensitivity of mechanical and cracking behaviors of tower crane braced frame joint with different embedded part parameters.

Numerical Simulation on the Mechanical Performance of the Wind Generator Latticed Concrete-Filled Steel Tubular Tower

2014 ◽  
Vol 578-579 ◽  
pp. 751-756
Author(s):  
Bin Li ◽  
Qun Hui Zhang ◽  
Chun Yan Gao
Keyword(s):  
Finite Element ◽  
Aspect Ratio ◽  
Bearing Capacity ◽  
Failure Mode ◽  
Mechanical Performance ◽  
Great Influence ◽  
Local Buckling ◽  
Ultimate Bearing Capacity ◽  
Thickness Ratio ◽  
Stiffness Ratio

Nonlinear finite element parameters analysis on the lattice type steel pipe concrete wind turbine tower, it shows the entire process of load bearing, failure mode and ultimate bearing capacity, researches on the influence law of aspect ratio, form of tower webs, tower diameter to thickness ratio and web member stiffness to tower column stiffness ratio on the ultimate bearing capacity and tower failure mode. The finite element analysis results shows that the tower aspect ratio λ, the diameter-thickness ratio γ of tower columns and the increase of stiffness ratio β between web members and tower columns has great influence on ultimate bearing capacity and failure mode, while the form of webs has small influence on that. with the increase of tower aspect ratio λ, the decrease of diameter-thickness ratio γ of tower columns and the increase of stiffness ratio β between web members and tower columns, the ultimate bearing capacity of this kind of latticed towers increase, the failure mode changed from Web local buckling to The combined damage of Web local buckling and the tension tower yield. This paper suggests that in the design of wind turbulent generator tower, the tower aspect ratio λ should be best controlled at 1/9, the bottom layers of this kind of tower should best use the re-divided web members, and other web member forms used on above layers, the diameter-thickness ratio γ of tower column should be taken less than 30, and the stiffness ratio β between webs and columns should be controlled less than 0.05 in order to avoid damage occurring on the tower columns earlier than the webs. The results can provide evidence for the engineering design.

The Study on Mechanical Properties of Single-Bolted Steel-Glulam-Steel Joints

2011 ◽  
Vol 255-260 ◽  
pp. 204-208 ◽  
Author(s):  
De Liang Xu ◽  
Wei Qing Liu ◽  
Ding Zhou ◽  
Jian Dong Ding ◽  
Ying Lei ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Bearing Capacity ◽  
Failure Mechanism ◽  
Failure Mode ◽  
Mechanical Performance ◽  
Timber Structures ◽  
Bolted Connections ◽  
Steel Connections ◽  
Steel Connection ◽  
Steel Joints

Seven groups, total of 31 single-bolted steel-glulam-steel joints, were tested for their mechanical performance. The mechanical properties of single-bolted steel-glulam-steel connection subjected to a load parallel to the grain have been studied. The failure mode and failure mechanism of bolted connections were discussed in detail. It is shown that the failure mode, bearing capacity, stiffness and ductility of the joint are mainly relative to the thickness of the glulam and the diameter of the bolt. Due to the wide application of bolted steel-glulam-steel connections in engineering, the present work can be taken as a reference in manufacture, and design of modern timber structures.

Study of Failure Modes of Suction Anchors

2011 ◽  
Author(s):  
Qiyi Zhang ◽  
Sheng Dong
Keyword(s):  
Finite Element ◽  
Bearing Capacity ◽  
Failure Mode ◽  
Failure Modes ◽  
Limit Equilibrium ◽  
Element Model ◽  
Ultimate Bearing Capacity ◽  
Engineering Practice ◽  
Element Analysis ◽  
Limit Equilibrium State

Suction foundations are widely used in deep sea and their ultimate bearing capacity which is closely related with failure modes of suction anchor at limit equilibrium state is a key technology in offshore engineering practice. Based on Coulomb friction theory, an exact finite element model is presented in this paper. On the basis of this FEM model, by use of the finite element analysis software ABAQUS, the effect of mooring point and aspect ratio of a suction anchor on the ultimate bearing capacity and its stability are researched in detail. The results show that the ultimate bearing capacity and stability of the suction anchor are affected vastly by the position of mooring point, and the variation of mooring point on the suction anchor can lead to different failure modes. Simultaneously, the results also shows that tilted rotation of the soil along the direction of the mooring force will occur when the mooring point is near the top of the suction anchor, and the soil near the bottom of the fixed anchor rotates around the center of a circle, so the failure mode is called forward-tilted rotation in this paper; A general translation slip of the soil in front of the anchor along the direction of the mooring force will occur when mooring point is below midpoint of suction anchor, so the failure mode is called the translation slip failure mode in this paper. Anticlockwise tilted rotation of the soil along the direction of mooting force will occur when the mooring point is near the bottom of the anchor, and the soil at the top of the anchor rotates around the center of a circle, so the failure mode is called backward-tilted rotation in this paper.

FE Nonlinear Analysis for Multiplanar CHS KK-Joint with in-Plane Gap and Out-of-Plane Overlap

2011 ◽  
Vol 94-96 ◽  
pp. 443-449
Author(s):  
Shi Qi Cui ◽  
Jian Dong Sun ◽  
Jun Li Lv ◽  
Chun Yang
Keyword(s):  
Bearing Capacity ◽  
Nonlinear Analysis ◽  
Failure Mechanism ◽  
Failure Mode ◽  
Ultimate Bearing Capacity ◽  
Failure Behavior ◽  
Displacement Curve ◽  
Absolute Value ◽  
Out Of Plane ◽  
Analysis Mode

On basis of the data from tests, FE nonlinear analysis mode on the multi-planar CHS KK-joints with in-plane gap and out-of-plane overlap (KK-OPOv) was advanced and validated in terms of failure mode, ultimate bearing capacity and etc. And the adaptability is reasonable. Moreover, FE nonlinear analysis for the joint on the typical load-displacement curve, failure behavior, failure mechanism and etc was conducted. The study suggests that the multi-planar KK-OPOv joints appear mainly in the CLD1 failure mode; at the time of failure, the tube wall deformations on the chords of multi-planar KK-OPOv joints and the corresponding planar K-Gap joints are coincide with each other basically. Both of these two types of joints are of a same failure mechanism; the multi-planar parameter ζt influences, to a certain extent, the ultimate bearing capacity on joints. That is, as the overlapping ratio of the out-of-plane braces is higher (namely, the absolute value of ζt increases), the ultimate bearing capacity of the joints decreases.

Experimental Study on the Ultimate Bearing Capacity of Partially Overlapped CHS-to-SHS Welded N-Joints

2011 ◽  
Vol 368-373 ◽  
pp. 473-477
Author(s):  
Xing Ping Shu ◽  
Zhi Shen Yuan ◽  
Zheng Rong Zhu ◽  
Yao Yao
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Bearing Capacity ◽  
Failure Mode ◽  
Side Wall ◽  
Axial Loading ◽  
Ultimate Bearing Capacity ◽  
Element Analysis ◽  
Hollow Section ◽  
Circular Hollow Section

This paper presents the experimental and numerical results of the ultimate bearing capacity of partially overlapped tubular N-joints, which have circular hollow section (CHS) brace members welded to a square hollow section (SHS) chord member. Two partially overlapped N-joints were tested to failure under overlapping brace axial loading and chord axial loading. The failure mode of specimen N1 was the overlapping brace local bucking, and the failure mode of specimen N2 was the chord face plastification with chord side wall buckling. Meanwhile, weld fracture occurred on both specimens. Then, making use of finite element package program ANSYS, in which twenty nodes solid element was employed and the weld was simulated, elastic-plastic large deflection finite element analysis of the experimental joints was conducted. The experimental data were compared with the results acquired by finite element analysis and it was proved that ANSYS is feasible to simulate the connecting weld and analyze the static behavior of partially overlapped CHS-to-SHS welded N-joints.

scholarly journals Experimental Study on Lightweight Precast Composite Slab of High-Titanium Heavy-Slag Concrete

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Jinkun Sun ◽  
Rita Yi Man Li ◽  
Nuttapong Jotikasthira ◽  
Kui Li ◽  
Liyun Zeng
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Fly Ash ◽  
Bearing Capacity ◽  
Silica Fume ◽  
Performance Test ◽  
Mechanical Performance ◽  
Ultimate Bearing Capacity ◽  
Element Analysis ◽  
Composite Slab

Precast composite slabs are an essential component in concrete-prefabricated buildings. At present, there are problems such as overweightedness and imperfect test for quality and structural performance of the precast floors, leading to restriction in the development of prefabricated buildings. In this study, by using industrial solid-waste high-titanium heavy slag as coarse and fine aggregates, with fly ash and silica fume for the partial substitution of the cement, we developed a green lightweight precast composite slab of high-titanium heavy-slag concrete (LPCSHTHSC) after adding shale ceramite as the light aggregate. By selecting the weight and the strength of LPCSHTHSC as the technical control indexes, we performed an orthogonal test of lightweight proportions. Through a comprehensive analysis of the compressive strength, splitting tensile strength, density, and an economic consideration, the optimal proportion was determined as follows: water-to-binder ratio of 0.43, mixing amount of the fly ash of 4%, mixing amount of the silica fume of 8%, mixing amount of the water-reducing agent of 0.5%, sand ratio of 35%, and cement at the strength grade of 42.5. Next, the bending performance test was conducted on LPCSHTHSC. According to the results, the LPCSHTHSC exhibited excellent mechanical performance, and its ultimate bearing capacity far exceeded the designed value. The ultimate bearing capacity calculated using the plastic hinge wire method differed slightly from the test value, suggesting the applicability of the proposed method to the calculation of the ultimate bearing capacity. Finally, the finite element analysis results of LPCSHTHSC were consistent with the actual bending mechanical performance test results, which proved both the accuracy and the reliability of the present finite element analysis based on the plastic damage constitutive model. The present study can provide an insightful theoretical and test foundation for the lightweight application of high-titanium heavy-slag concrete in other prefabricated components.

scholarly journals Damage Constitutive Model and Mechanical Performance Deterioration of Concrete under Sulfate Environment

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Peng Liu ◽  
Ying Chen ◽  
Zhiwu Yu ◽  
Zhaohui Lu
Keyword(s):  
Mechanical Properties ◽  
Bearing Capacity ◽  
Elasticity Modulus ◽  
Mechanical Performance ◽  
Sulfate Solution ◽  
Concrete Surface ◽  
Ultimate Bearing Capacity ◽  
Stress Strain ◽  
Before And After ◽  
Relationship Model

The effects of erosion mode, erosion age, and concentration of sulfate solution on mechanical properties of concrete were investigated. The dimensionless relationship model of the stress-strain of concrete on the basis of randomness was proposed. The variation of the elasticity modulus and Poisson’s ratio of the concrete surface attacked by sulfate was studied, and a novel method of using a superficial parameter to characterize the performance change of the concrete surface was recommended. The results showed that the dimensionless relationship model of stress-strain of concrete could be used to represent the variations of mechanical properties of concrete. The differences of load-displacement of concrete before and after sulfate attack were reflected as the change of curve’s slope and ultimate bearing capacity, and the slope of a straight section of the lateral and longitudinal strain curves of concrete surface also varied. The increment rates of ultimate bearing capacity of concrete attacked by 1% and saturated sulfate solution were about 30% and 10%, respectively. However, the decreasing ratio of the ultimate bearing capacity of concrete attacked by saturated sulfate solution was approximately 25%. The damage factor of the elasticity modulus of the concrete surface of C20 and C40 was 0.185 and −0.19, respectively. The obtained results could provide a support for investigating the variations of stress-strain relationship and mechanical performance of concrete under a sulfate environment.

Hysteretic Behavior of Composite Vertical Connection Structures used in Prefabricated Shear Wall Systems

2020 ◽  
Vol 20 (06) ◽  
pp. 2040007
Author(s):  
Limeng Zhu ◽  
Haipeng Yan ◽  
Po-Chien Hsiao ◽  
Jianhua Zhang
Keyword(s):  
Finite Element ◽  
Bearing Capacity ◽  
High Strength Steel ◽  
Failure Modes ◽  
Mechanical Performance ◽  
Shear Walls ◽  
High Strength ◽  
Shear Wall ◽  
Hysteretic Behavior ◽  
Design Standards

An innovative composite vertical connecting structure (CVC) with capacity carrying and energy-dissipating ability is proposed in this study, which could be used in prefabricated composite shear wall structural systems to enhance the resilience and seismic performance of structural system. The CVC structure is mainly composed of three parts, including the connecting zone, the capacity bearing zone characterized by high strength and elastic deforming ability, and the energy-dissipating zone assembled by replaceable metal dampers. The low-yield strength steel and high-strength steel are used, respectively, for the metal dampers in the energy-dissipating zone and the concrete-filled high-strength steel tubes in the bearing capacity zone to enhance the energy dissipation and self-centering abilities of CVC structures. The working mechanism is analyzed and validated through finite element models built in ABAQUS. The hysteretic behavior is simulated to evaluate their performance. First, the metal dampers are designed. The theoretical and finite elemental parametric analysis are carried out. According to the simulation results, the “Z-shaped” metal dampers exhibit better energy-dissipating ability than the rectangular shape, in which the “Z-shaped” metal dampers with 45∘ show the best performance. Simultaneously, the results of the models calculated by the finite element method and theoretical analysis work very well with each other. Furthermore, seven FE models of shear walls with CVC structures are designed. Monotonic and cyclic loading simulations are conducted. The failure modes and comprehensive mechanical performance are investigated and evaluated according to their calculated force–displacement curves, skeleton curves, and ductility coefficients. The results indicate that the CVC structure delivered preferable lateral-bearing capacity and displacement ductility. Finally, according to available design standards, the lateral stiffness of CVC structures could be conventionally controlled and some practical design recommendations are discussed.

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