scholarly journals Stability of pinned-rotationally restrained arches

2020 ◽  
pp. 10-10
Author(s):  
László Kiss
Keyword(s):  
Nonlinear Model ◽  
Bending Moment ◽  
Geometrically Nonlinear ◽  
Vertical Force ◽  
Material Distribution ◽  
Nonlinear Load ◽  
Buckling Loads ◽  
Strain Relationship ◽  
Membrane Strain ◽  
End Restraint

The article aims to find the buckling loads for pinned-rotationally restrained shallow circular arches in terms of the rotational end stiffness, geometry and material distribution. The loading is a concentrated vertical force placed at the crown. A geometrically nonlinear model is presented which relates not only the axial force but also the bending moment to the membrane strain. The nonlinear load-strain relationship is established between the strain and load parameters. This equation is then solved and evaluated analytically. It turns out that the stiffness of the end-restraint has, in general, a significant effect on the lowest buckling load. At the same time, some geometries are not affected by this. As the stiffness becomes zero, the arch is pinned-pinned and as the stiffness tends to infinity, the arch behaves as if it were pinned-fixed and has the best load-bearing abilities.

scholarly journals Analytical Method for Geometric Nonlinear Problems Based on Offshore Derricks

Mathematics ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 610
Author(s):  
Chunbao Li ◽  
Hui Cao ◽  
Mengxin Han ◽  
Pengju Qin ◽  
Xiaohui Liu
Keyword(s):  
Analytical Method ◽  
Bending Moment ◽  
Nonlinear Problems ◽  
Weather Conditions ◽  
Order Effect ◽  
Practical Calculation ◽  
Geometrically Nonlinear ◽  
Uniform Load ◽  
Safety Research ◽  
Calculation Results

The marine derrick sometimes operates under extreme weather conditions, especially wind; therefore, the buckling analysis of the components in the derrick is one of the critical contents of engineering safety research. This paper aimed to study the local stability of marine derrick and propose an analytical method for geometrically nonlinear problems. The rod in the derrick is simplified as a compression rod with simply supported ends, which is subjected to transverse uniform load. Considering the second-order effect, the differential equations were used to establish the deflection, rotation angle, and bending moment equations of the derrick rod under the lateral uniform load. This method was defined as a geometrically nonlinear analytical method. Moreover, the deflection deformation and stability of the derrick members were analyzed, and the practical calculation formula was obtained. The Ansys analysis results were compared with the calculation results in this paper.

On compliance with the requirements of Federal Law No. 384-FL «Technical Regulations on the safety of buildings and structures» in the design of foundations and foundations of bridges

Innotrans ◽  
2021 ◽  
pp. 31-37
Author(s):  
Alexey N. Alekhin ◽  
◽  
Andrey A. Alekhin ◽  
Keyword(s):  
Cost Effectiveness ◽  
Nonlinear Model ◽  
Master's Degree ◽  
Geometrically Nonlinear ◽  
Practical Application ◽  
Federal Law ◽  
Effective Training ◽  
Master’S Degree ◽  
Design Solutions ◽  
Technical Regulations

The article discusses the issue of complying with the requirements of Article 16 of Federal Law No. 384-FL «Technical Regulations on the safety of buildings and structures» on the use of a physically and geometrically nonlinear model adequate to the soil when developing the bases and foundations of bridge supports and other transport structures, which will significantly increase the reliability and cost-effectiveness of design solutions. At the same time, it is necessary to adjust the methodological and instrument support of transport universities for the effective training of bachelor’s and master’s degree students in the methodology of practical application of the geotechnical requirements of Law No. 384-FL.

Application of the Nonlinear Model of a Beam for Investigation of Interlaminar Fracture Toughness of Layered Composite

2015 ◽  
Vol 665 ◽  
pp. 273-276 ◽  
Author(s):  
Vitalijs Pavelko
Keyword(s):  
Fracture Toughness ◽  
Nonlinear Model ◽  
Geometrical Nonlinearity ◽  
Local Effect ◽  
Layered Composite ◽  
Flexible Beam ◽  
Geometrically Nonlinear ◽  
Interlaminar Fracture Toughness ◽  
Linear Solution ◽  
Interlaminar Fracture

Earlier presented the geometrically nonlinear model of a flexible beam (cylindrical bending of a plate) was used for analysis of post-buckling behavior of the layered composite with delamination at compression. In this paper the model is used for more details nonlinear analysis of double cantilever beam (DCB) that used in standard test for determination of the interlaminar fracture toughness composites with delamination-type damage. The main advantage of the model is a precise description of the curved axis of the beam (plate) without linearization or other higher order approximations. The exact solution of bending differential equation finally can be expressed in terms of the incomplete elliptic integrals of the first and second kind. The model describes only geometrically nonlinear effect of DCB arms bending (global effect) and should be combined with the procedure of effective delamination extension to correct DCB arms rotation at delamination front (local effect). First of all the nonlinear model can serve as a tool to estimate the possible error due the geometrical nonlinearity in comparison with linear solution. On the other hand, this model can be effectively used to determine interlaminar fracture toughness using DCB samples at large deflections. Validation of the model is made using data of standard tests of glass/epoxy DCB samples.

scholarly journals Finite Element Analysis and Parametric Study of Spudcan Footing Geometries Penetrating Clay Near Existing Footprints

2019 ◽  
Vol 7 (6) ◽  
pp. 175 ◽  
Author(s):  
Long Yu ◽  
Heyue Zhang ◽  
Jing Li ◽  
Xian Wang
Keyword(s):  
Bending Moment ◽  
Vertical Force ◽  
Leg Length ◽  
Element Analysis ◽  
Centrifuge Tests ◽  
Flat Base ◽  
Key Factor ◽  
The Stability ◽  
Resultant Forces ◽  
Theoretical Analyses

Most existing research on the stability of spudcans during reinstallation nearing footprints is based on centrifuge tests and theoretical analyses. In this study, the reinstallation of the flat base footing, fusimform spudcan footing and skirted footing near existing footprints are simulated using the coupled Eulerian–Lagrangian (CEL) method. The effects of footprints’ geometry, reinstallation eccentricity (0.25D–2.0D) and the roughness between spudcan and soil on the profiles of the vertical force, horizontal force and bending moment are discussed. The results show that the friction condition of the soil–footing interface has a significant effect on H profile but much less effect on M profile. The eccentricity ratio is a key factor to evaluate the H and M. The results show that the geometry shape of the footing also has certain effects on the V, H, and M profiles. The flat base footing gives the lowest peak value in H but largest in M, and the performances of the fusiform spudcan footing and the skirted footing are similar. From the view of the resultant forces, the skirted footing shows a certain potential in resisting the damage during reinstallation near existing footprints by comparing with commonly used fusiform spudcan footings. The bending moments on the leg–hull connection section of different leg length at certain offset distances are discussed.

Large deflection of elastoplastic, non-linear strain-hardening cantilevers

2001 ◽  
Vol 216 (4) ◽  
pp. 433-446 ◽  
Author(s):  
X Huang ◽  
B Wang ◽  
G Lu ◽  
T X Yu
Keyword(s):  
Strain Hardening ◽  
Large Deflection ◽  
Rectangular Cross Section ◽  
Bending Moment ◽  
Linear Strain ◽  
Non Linear ◽  
Theoretical Predictions ◽  
Strain Relationship ◽  
Inclined Angle ◽  
Good Agreement

This paper concerns the large deflection of elastoplastic, non-linear strain-hardening cantilevers of rectangular cross-section, for which the stress-strain relationship after yielding is described by σ= K1εq. Both the bending moment and axial force are included in the yielding criterion, and the corresponding strain increments obey the associated normality rule. Comparisons between the experimental data and the theoretical predictions are made for mild steel cantilevers subjected to a tip force with an inclined angle ϕ = 67.5,90 and 157° respectively. Reasonable agreement is obtained. The theoretical analysis has described the large deflection behaviour of the cantilever and is in good agreement with tests.

Delamination Buckling of Kevlar and Twaron Stitched Glass\Epoxy Composite Laminates by Experiments

2008 ◽  
Vol 136 ◽  
pp. 109-114
Author(s):  
Madusudhanan R. Parlapalli ◽  
Kwok C. Soh ◽  
Dong Wei Shu
Keyword(s):  
Composite Laminates ◽  
Epoxy Composite ◽  
Flexural Modulus ◽  
Vertical Displacement ◽  
Buckling Loads ◽  
Buckling Strength ◽  
Different Types ◽  
Delamination Buckling ◽  
Membrane Strain ◽  
Delamination Length

In the present paper, effects of through-the-thickness stitching of delaminated glass/epoxy composite laminates with two different types of aramid threads, Kevlar® and Twaron® threads, on the buckling loads are studied. The buckling loads are predicted based on the Southwell, Vertical displacement and Membrane strain plot methods from the experimental data. Flexural modulus of the stitched and unstitched glass/epoxy composite laminates, knot tensile strength of Kevlar® and Twaron® stitching threads are obtained experimentally. From the Southwell, Vertical displacement and Membrane strain plot methods it is observed that stitching either by Kevlar® or Twaron® threads is effective in improving the buckling strength of glass/epoxy composite laminates when the delamination length is greater than 0.5L, L is the length of the laminate.

Analytical Buckling Loads of Composite Rectangular Plates with Vertical and Rotational Springs Along the Edges

2020 ◽  
pp. 2043002
Author(s):  
Joseph Tenenbaum ◽  
Moshe Eisenberger
Keyword(s):  
Boundary Conditions ◽  
Bending Moment ◽  
Composite Plates ◽  
Static Solution ◽  
Published Data ◽  
Rectangular Plates ◽  
Buckling Loads ◽  
Edge Conditions ◽  
In Series ◽  
Edge Force

In this research, a new analytical solution is used for finding the buckling loads of rectangular plates with vertically and rotationally restrained edges. The solution method in this study is based on the development of a static solution for a plate. The solution is obtained in series form, and the coefficients are solved to match the edge conditions. The solution fits all the combinations of possible boundary conditions, of the deflection, slope, shear force and bending moment along the edges of the plate. In the case of springs, the edge force and moment boundary conditions are modified to include these effects. Any number of edges, from one to four, with both types of stiffening springs can be solved. Using this new method, the exact buckling loads and modes are found. The results are verified with published data, and many new cases are presented for uni-axially and bi-axially loaded isotropic, orthotropic, and composite plates.

scholarly journals Assessment on Segment Joint to Improve Soil-Tunnel Interaction

2018 ◽  
Vol 250 ◽  
pp. 01005
Author(s):  
Siti Norafida Jusoh ◽  
Hisham Mohamad ◽  
Aminaton Marto ◽  
Fauziah Kassim
Keyword(s):  
Nonlinear Model ◽  
Field Data ◽  
Ground Deformation ◽  
Ground Surface ◽  
Bending Moment ◽  
Settlement Pattern ◽  
Tunnel Lining ◽  
Tunnel Construction ◽  
Joint Modelling ◽  
Tunnel Model

The bending moment of tunnel lining can be influenced by non-uniform ground pressures and joint eccentricities. Influence of joint interaction that induces flexural moment behaviour in segmental tunnel lining was investigated for the project Circle Line Stage 3 (C852), Serangoon Interchange Station. By considering behaviour of segment joint (which can affects the tunnel circumferential and longitudinal safety in overall), the tunnel lining behaviour and displacement of the ground surrounding the tunnel were evaluated. The segment joint modelling in simplified dual-jointed model and in fully soil-tunnel model were developed to assess the effect of segment joint on the overall tunnel response. Ground deformation or settlement trough at the ground surface resulted from the effect of tunnel construction and interaction between soil, tunnel, segment joints and ring joints was predicted. Results showed that with different use of segment joints give different longitudinal settlement. Hinge-nonlinear model together with separated rings model lead to the highest resemblance of surface settlement pattern to the field data when compare to tie model.

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