scholarly journals Numerical Analysis of the Structural Stability of Ideal (Defect-Free) and Structurally and Morphologically Degenerated Homogeneous, Linearly- and Angle-Adjoined Nanotubes and Cylindrical Fullerenes Under Axial Loading Using Finite Element Method

2018 ◽  
Vol 10 (09) ◽  
pp. 1850100
Author(s):  
Sadegh Imani Yengejeh ◽  
Andreas Öchsner ◽  
Seyedeh Alieh Kazemi ◽  
Maksym Rybachuk
Keyword(s):  
Finite Element Method ◽  
Carbon Nanotubes ◽  
Finite Element ◽  
Critical Load ◽  
Structural Stability ◽  
Carrying Capacity ◽  
Axial Loading ◽  
Structural Defects ◽  
Load Carrying Capacity ◽  
Load Carrying

We report on the structural stability of ideal (defect-free) and structurally and morphologically degenerate carbon nanotubes and nanotube junction systems under axial loading based on the finite element method. We estimated the values for critical buckling load for uncapped and capped single-walled carbon nanotubes (SWCNTs) and linear and angle-adjoined SWCNT heterojunctions in ideal and structurally degenerate systems containing single-, double-, triple-, pinhole- and pentagon–heptagon (i.e., 5–7) structural defects and also containing a substitutional nitrogen (N) atom inclusion under compressive loading. Absolute atomic vacancy (defect) concentration in studied SWCNTs models was assumed to be nil for ideal systems, and was up to 3.0 at.% for structurally and morphologically degenerate systems. It was found that all types of structural defects and the morphological N-defect had reduced the load carrying capacity and mechanical strength in all SWCNT systems studied. The SWCNT models containing physically large vacant sites, such as triple- and pinhole-defects, displayed significantly lower critical load values compared to the systems that contained only a single-, double- or triple-vacancies. In addition, we found that capped SWCNTs performed marginally better in critical load carrying capacity compared to uncapped SWCNT systems. Furthermore, majority of the investigated structures displayed reduced load in SWCNTs with narrower tube widths, proportional to the size and the type of the defect investigated. The effects of chirality, such as zigzag- versus armchair-type, on the structural stability of the investigated SWCNT models were also investigated.

Determination of the Load Carrying Capacity of Honeycomb Panels at Fixing Points under an External Load

2020 ◽  
Vol 299 ◽  
pp. 1184-1189
Author(s):  
V.V. Zhukov ◽  
Anton V. Eremin ◽  
D.V. Stepanec
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Finite Element Model ◽  
Carrying Capacity ◽  
External Load ◽  
Element Model ◽  
Load Carrying Capacity ◽  
The Finite Element Method ◽  
Load Carrying ◽  
Honeycomb Panel

In this article, the object of study is a three–layer honeycomb panel with fixing elements (FE), which are used for transporting the panel, and fixing it to the spacecraft. The goal of the work is to determine experimentally the load carrying capacity of the fixing elements under various types of loading, to determine the load carrying capacity of the honeycomb panel of the spacecraft at fixing points and further comparison of the experimental results with the finite element method results calculated by MSC.Patran / Nastran. A method for conducting static tests of fixing elements of a spacecraft honeycomb panel under an external load is described, a description of computer technology of a finite–element solution to the problem of static strength of a honeycomb panel structure in the MSC.Patran environment is presented, and a finite–element model of a honeycomb panel is designed. An assessment of the strength of a three–layer structure at fixing points was carried out, followed by validation of the finite–element model of a honeycomb panel. On the basis of the validated model, the evaluation of the strength of the honeycomb structure was carried out; based on results obtained, the conclusion has been made about the convergence of the results by the finite element method with the results obtained during the experiment.

SEARCH FOR THE MOST USEFUL GEOMETRY OF AN ACOUSTIC JOURNAL BEARING

Tribologia ◽  
2018 ◽  
Vol 273 (3) ◽  
pp. 15-66 ◽  
Author(s):  
Rafał GAWARKIEWICZ
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Computer Simulations ◽  
Carrying Capacity ◽  
Journal Bearing ◽  
Squeeze Film ◽  
Acoustic Levitation ◽  
Load Carrying Capacity ◽  
The Finite Element Method ◽  
Load Carrying

Computer simulations of a number of journal bearing’s geometries utilising acoustic levitation were carried out. The choice of the best geometry depended on the ability of a deformed shape, created by piezo-electric elements, to facilitate squeeze film ultrasonic levitation, and also to create three evenly distributed diverging aerodynamic gaps. Deformations of analysed variants of the bearing’s shape were generated by numerical simulations utilising the finite element method. For the chosen shapes of geometry, prototype bearings were made and their usefulness verified experimentally. As a result, the bearing with the highest load carrying capacity was identified.

Single-angle compression members welded by one leg to a gusset plate. II. A parametric study and design equation

1998 ◽  
Vol 25 (3) ◽  
pp. 585-594 ◽  
Author(s):  
Murray C Temple ◽  
Sherief SS Sakla
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Carrying Capacity ◽  
Load Carrying Capacity ◽  
Design Equation ◽  
Rigid Support ◽  
The Finite Element Method ◽  
Gusset Plate ◽  
Compression Members ◽  
Load Carrying

Single-angle compression members are complex members to analyze and design. The two generally accepted design procedures, the simple-column and the beam-column approaches, in general, underestimate the load-carrying capacity of single-angle compression members welded by one leg to a gusset plate fixed to a rigid support. One of the reasons is that these approaches do not properly account for the end constraint provided by the gusset plate. The effective length factor can be adjusted, but this is difficult to do as the end restraint is not easy to evaluate in many practical cases. Another reason is that these approaches are not based on a rational understanding of the failure mechanism of these members. An experimental program confirmed that the finite element method can be used, with a reasonable degree of accuracy, to predict the behavior and load-carrying capacity of single-angle compression members welded by one leg to a gusset plate fixed to a rigid support. The finite element method was used to study some 1800 different combinations of parameters. It was found that out-of-straightness, residual stresses in the angle section, Young's modulus of elasticity, and the unconnected gusset plate length do not have a great effect on the load-carrying capacity. The most significant parameter is the gusset plate thickness with the gusset plate width being the second most important parameter. An empirical design equation is proposed.Key words: angles, buckling, columns (structural), compressive resistance, design equation, gusset plates.

scholarly journals Calculation Method for Load-Carrying Capacity of Circular Reinforced Con

2021 ◽  
Vol 353 ◽  
pp. 01013
Author(s):  
Tingwei Wang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Reinforced Concrete ◽  
Carrying Capacity ◽  
Steel Tube ◽  
Experimental Result ◽  
Load Carrying Capacity ◽  
Model Method ◽  
Concrete Members ◽  
Load Carrying

Finite element method and fiber model method were used to calculate the load-carrying capacity of the specimens. Based on the experimental and theoretical analysis, simplified calculation method of the load-carrying capacity for this kind of member is proposed. It indicates that finite element method result is relatively small, fiber model method result accords well with the experimental result. Circular reinforced concrete members covered with steel tube presents both the characteristics of reinforced concrete and concrete filled steel tube member, showing higher load-carrying capacity and greater deformability. The load-carrying capacity of circular reinforced concrete members covered with steel tube can be calculated by the means of the method of reinforced concrete member with confined concrete. The result predicted by the simplified method is in good agreement with the experimental result.

scholarly journals Experimental and Numerical Analysis of Steel Joints in Round Wood

2014 ◽  
Vol 14 (2) ◽  
pp. 1-10 ◽  
Author(s):  
David Mikolášek ◽  
Antonín Lokaj ◽  
Jiří Brožovský ◽  
Oldřich Sucharda
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Analysis ◽  
Carrying Capacity ◽  
Load Carrying Capacity ◽  
The Finite Element Method ◽  
Geometrical Nonlinearities ◽  
Round Wood ◽  
Load Carrying ◽  
Steel Joints

Abstract The paper analyses a drawn steel joint in round logs for which several types of reinforcements have been proposed. The load-carrying capacity of the reinforcements have been tested in laboratories. At the same time, numerical modelling has been performed - it has focused, in particular, on rigidity of the joints during the loading process. Physical and geometrical nonlinearities have been taken into account. The Finite Element Method and 3D computation models have been used in the numerical calculations.

Evaluation on ultimate load-carrying capacity of concrete-filled steel tubular arch structure with preload

2019 ◽  
Vol 22 (13) ◽  
pp. 2755-2770
Author(s):  
Fuyun Huang ◽  
Yulong Cui ◽  
Rui Dong ◽  
Jiangang Wei ◽  
Baochun Chen
Keyword(s):  
Finite Element ◽  
Initial Stress ◽  
Carrying Capacity ◽  
Ultimate Load ◽  
Load Carrying Capacity ◽  
Test Results ◽  
Arch Bridge ◽  
Load Carrying ◽  
Arch Structure ◽  
Ultimate Load Carrying Capacity

When casting wet concrete into hollow steel tubular arch during the construction process of a concrete-filled steel tubular arch bridge, an initial stress (due to dead load, etc.) would be produced in the steel tube. In order to understand the influence of this initial stress on the strength of the concrete-filled steel tubular arch bridge, a total of four single tubular arch rib (bare steel first) specimens (concrete-filled steel tubular last) with various initial stress levels were constructed and tested to failure. The test results indicate that the initial stress has a large influence on the ultimate load-carrying capacity and ductility of the arch structure. The high preloading ratio will reduce significantly the strength and ductility that the maximum reductions are over 25%. Then, a finite element method was presented and validated using the test results. Based on this finite element model, a parametric study was performed that considered the influence of various parameters on the ultimate load-carrying capacity of concrete-filled steel tubular arches. These parameters included arch slenderness, rise-to-span ratio, loading method, and initial stress level. The analysis results indicate that the initial stress can reduce the ultimate loading capacity significantly, and this reduction has a strong relationship with arch slenderness and rise-to-span ratio. Finally, a method for calculating the preloading reduction factor of ultimate load-carrying capacity of single concrete-filled steel tubular arch rib structures was proposed based on the equivalent beam–column method.

Structural Behaviour of Precast Lightweight Foamed Concrete Sandwich Panel (PLFP) with Double Shear Truss Connectors under Axial Load: Preliminary Result

2013 ◽  
Vol 795 ◽  
pp. 190-194
Author(s):  
S. Samsuddin ◽  
I. Ahmad ◽  
W.I. Goh ◽  
N. Mohamad ◽  
Abdul Aziz Abdul Samad ◽  
...  
Keyword(s):  
Experimental Data ◽  
Carrying Capacity ◽  
Ultimate Load ◽  
Axial Loading ◽  
Load Carrying Capacity ◽  
Structural Behaviour ◽  
Double Shear ◽  
Load Carrying ◽  
Foamed Concrete ◽  
Ultimate Load Carrying Capacity

This report provides experimental data on the development of PLFP for building construction. An innovative concept was used in the design of this system and the use of lightweight foamed concrete was discussed. Preliminary result of PLFP with double shear truss connectors was analysed and presented. PLFP was tested to determine its ultimate load carrying capacity under axial loading. Ultimate load carrying capacity, load deflection profile, surface strains and crack pattern were recorded and analysed. Test results were compared with calculated values based on classical formulas that developed by previous researchers and experimental data from previous researchers on its compositeness in between wythes. Results shown that PLFP with double shear truss connectors achieved higher compositeness in between wythes and have adequate ultimate load carrying capacity.

Experimental Study for Single-Angle Beam-Column Members Attached by one Leg

2010 ◽  
Vol 163-167 ◽  
pp. 433-438
Author(s):  
Xian Lei Cao ◽  
Ji Ping Hao ◽  
Chun Lei Fan
Keyword(s):  
Experimental Study ◽  
Finite Element ◽  
Carrying Capacity ◽  
Model Experiment ◽  
Ultimate Load ◽  
High Strength ◽  
Load Carrying Capacity ◽  
Compression Members ◽  
Load Carrying ◽  
Ultimate Load Carrying Capacity

To obtain a better understanding of the behavior and load-carrying capacity of Q460 high-strength single-angle compression members bolted by one leg, using static loading way to 48 angles carried out experimental study. The experiments show test specimens produce biaxial bending, most small slenderness ratio members are controlled by local buckling, and slender specimens are controlled by overall buckling. In addition to these factors in model experiment, influences of residual stresses on ultimate load-carrying capacity were analyzed by finite element numerical simulation analysis, the results show the residual stresses affect the ultimate load-carrying capacity of angles by about 5％ or less. Comparison of the load-carrying capacity of experimental and theoretical results indicate the difference of experimental and finite element values ranges from -9.99％ to +9.76％, American Design of Latticed Steel Transmission Structure (ASCE10-1997) and Chinese Code for Design of Steel Structures (GB50017-2003) underestimate separately the experimental load-carrying capacity by about 2.34％～33.93％ and 1.18％～63.3％, and the agreement is somewhat good between experimental program and the finite element analysis. Based on model experiment and simulated experiment, the formula of stability coefficient of single-angle compression members was established. It provides basic data for spreading Q460 high-strength single-angles members attached by one leg.

Analysis of the Load-Carrying Capability of the Casing Plug Joint of Steel Tube Structures Considering the Contact Effect

2008 ◽  
Vol 33-37 ◽  
pp. 321-326 ◽  
Author(s):  
Xiu Gen Jiang ◽  
Yang Yang ◽  
Feng Jie Zhang ◽  
Jin San Ju ◽  
Xiao Chuan You
Keyword(s):  
Finite Element ◽  
Carrying Capacity ◽  
Element Model ◽  
Steel Tube ◽  
Nonlinear Finite Element ◽  
Tube Length ◽  
Load Carrying Capacity ◽  
Ansys Software ◽  
Load Carrying ◽  
Nonlinear Finite Element Model

Nonlinear finite element model analysis of the casing plug joints of steel tubular has been realized by ANSYS software. The law of load-carrying capability and stiffness of joint are separately gained by changing the ratio of length and diameter (R/L) and the ratio of the casing length and the main tube length (l/L). The influence of the casing thickness on the load-carrying capability and stiffness are also discussed. The results indicated that the load-carrying capability and stiffness of the joints both increase with the ratio(R/L) increment and the ratio of the casing length and main tube length (l/L). When the main tube thickness is equal to casing thickness, the load-carrying capacity of joints achieves the most.

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