scholarly journals Mechanical Performance and Parameter Sensitivity Analysis of 3D Braided Composites Joints

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Yue Wu ◽  
Bo Nan ◽  
Liang Chen
Keyword(s):  
Sensitivity Analysis ◽  
Bearing Capacity ◽  
Mechanical Performance ◽  
Ultimate Bearing Capacity ◽  
Pipe Diameter ◽  
Composite Joints ◽  
Braided Composite ◽  
Main Pipe ◽  
Strength Failure ◽  
3D Braided Composites

3D braided composite joints are the important components in CFRP truss, which have significant influence on the reliability and lightweight of structures. To investigate the mechanical performance of 3D braided composite joints, a numerical method based on the microscopic mechanics is put forward, the modeling technologies, including the material constants selection, element type, grid size, and the boundary conditions, are discussed in detail. Secondly, a method for determination of ultimate bearing capacity is established, which can consider the strength failure. Finally, the effect of load parameters, geometric parameters, and process parameters on the ultimate bearing capacity of joints is analyzed by the global sensitivity analysis method. The results show that the main pipe diameter thickness ratioγ, the main pipe diameterD, and the braided angleαare sensitive to the ultimate bearing capacityN.

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.

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.

scholarly journals Analysis on the Mechanical Performance of the Joints of the Wheel-coupler type formwork Support

2021 ◽  
Vol 261 ◽  
pp. 02070
Author(s):  
Shilong Jia ◽  
Fang Zhou ◽  
Zhongliang Chen
Keyword(s):  
Mechanical Properties ◽  
Bearing Capacity ◽  
Mechanical Performance ◽  
Ultimate Bearing Capacity ◽  
Displacement Curve ◽  
Ansys Software ◽  
Rotational Stiffness ◽  
Non Linear ◽  
Tension And Compression ◽  
Load Displacement

In order to study the mechanical properties of the joints, ANSYS software was used to simulate and analyse the failure form, ultimate bearing capacity, load-displacement curve and the rotational stiffness of the wheel-coupler joint node under force. Results: The wheel-coupler joint node has obvious non-linear characteristics when subjected to force; The bilateral symmetric tension and compression state could better reflect the failure form and deformation of the joint; The rotational stiffness of the wheel-coupler joint node under tension and bending was greater than that under bending and torsion, and was greater than that under tension, bending and torsion.

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.

scholarly journals Mechanical performance study of the retractable pier column after stiffening

2020 ◽  
Vol 7 (4) ◽  
pp. 725-739
Author(s):  
Yi Zhang ◽  
Xiaoye Wang ◽  
Liming Zhao ◽  
Jie Liu ◽  
Nana Wang ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Axial Compression ◽  
Mechanical Performance ◽  
Ultimate Bearing Capacity ◽  
Steel Pipe ◽  
Practical Significance ◽  
Scale Model ◽  
Optimal Size ◽  
Filling Material ◽  
Performance Study

AbstractTo solve the problem that the overlapping parts of a retractable pier column are prone to damage, this paper proposed the reinforcing measure of setting a stiffener ring at the bottom of the steel pipe. To study how the stiffener-ring parameters influence the mechanical properties of the pier column, 12 scale model specimens (including nine specimens with stiffener-ring widths of 40, 50, and 60 mm and three unstiffened comparison specimens) were tested under axial compression. Based on the test results, the specimen load–displacement, load–deflection, and load–strain curves were analyzed, and a finite-element model of a pier column under axial compression was established to determine the optimal stiffener size. The results show that setting a stiffener ring enhances the cooperative working ability between the steel pipe and the internal filling material and restrains the lateral deformation of the pier column, thereby improving the ultimate bearing capacity and overall stability of the pier column. The ultimate bearing capacity of the pier column is related to the width and thickness of the stiffener ring. The optimal size of the stiffener ring of the model pier column is 70 mm in width and 4 mm in thickness. The present research results provide a reference for designing compressible pier columns and column stiffening in mines and have important practical significance.

A Calculation Method of Ultimate Torsional Strength for Subsea Collet Connector Based on Finite Element Method

2016 ◽  
Author(s):  
Kang Zhang ◽  
Menglan Duan ◽  
Xiaolan Luo ◽  
Yi Hong
Keyword(s):  
Finite Element ◽  
Bearing Capacity ◽  
Failure Criterion ◽  
Calculation Method ◽  
Ultimate Bearing Capacity ◽  
Design Parameters ◽  
Damage Resistance ◽  
Torsional Strength ◽  
Strength Failure ◽  
Sealing Failure

Subsea connector is an important connection facility in subsea production system. Once destroyed, it will cause sealing failure which could lead to leakage accident, so the connectors must have high degree of damage-resistance capacity. Ultimate bearing capacity is composed of a set of important parameters measuring subsea connectors’ damage-resistance capacity, such as ultimate bending strength, ultimate torsional strength, etc. However, these data are usually obtained by carrying out destructive tests, which will bring heavy cost to subsea connector products in order to obtain the required technical data. Considering reducing the cost of destructive testing, a theoretical calculation method is needed to be developed. In addition, during the stage of product design, it is also necessary to estimate ultimate bearing capacity to verify whether the structural design parameters meet the anticipated requirements. In this paper, only the ultimate torsional strength of subsea connectors was studied, and based on finite element analysis, a calculation method of ultimate torque was put forward, which consists of using finite element software to build the 3D subsea connector model, loading different pure torsional moment, analyzing the calculation results and establishing torsional failure criteria to determine ultimate torsional strength. The results show that sealing failure will be ahead of structural strength failure under the pure torsional loads, and traditional strength failure criterion is not suitable for determining ultimate torsional strength of subsea connectors; the numerical solution of ultimate torque is 60KN·m based on the sealing failure criterion in this paper. In the end, a simplified mechanical model of subsea connector was established, the limit state equation of sealing failure was built in the action of pure torsional load, and the analytical solution of ultimate torque was calculated. The calculation method of ultimate torsional strength established in this paper was verified through comparative analysis.

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.

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