A Predictive Technique for Buckling Analysis of Thin Section Panels Due to Welding

1996 ◽  
Vol 12 (04) ◽  
pp. 269-275
Author(s):  
Panagiotis Michaleris ◽  
Andrew DeBiccari

This paper presents an efficient and effective numerical analysis technique for predicting welding-induced buckling. The technique combines three-dimensional structural analyses with two-dimensional welding simulations. Implementation of the technique can determine the appropriate welding conditions under which the design critical buckling load is not exceeded. Experimental results obtained from small-and large-scale mock-up panels are used to confirm the predictions of the analytical models, The paper concludes with a study of the effects of heat input (weld size), panel size, and panel thickness on buckling distortion.

Geosciences ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 76
Author(s):  
Ashraf Hefny ◽  
Mohamed Ezzat Al-Atroush ◽  
Mai Abualkhair ◽  
Mariam Juma Alnuaimi

The complexities and the economic computational infeasibility associated in some cases, with three-dimensional finite element models, has imposed a motive for many investigators to accept numerical modeling simplification solutions such as assuming two-dimensional (2D) plane strain conditions in simulation of several supported-deep excavation problems, especially for cases with a relatively high aspect ratio in plan dimensions. In this research, a two-dimensional finite element model was established to simulate the behavior of the supporting system of a large-scale deep excavation utilized in the construction of an underground metro station Rod El Farrag project (Egypt). The essential geotechnical engineering properties of soil layers were calculated using results of in-situ and laboratory tests and empirical correlations with SPT-N values. On the other hand, a three-dimensional finite element model was established with the same parameters adopted in the two-dimensional model. Sufficient sensitivity numerical analyses were performed to make the three-dimensional finite element model economically feasible. Results of the two-dimensional model were compared with those obtained from the field measurements and the three-dimensional numerical model. The comparison results showed that 3D high stiffening at the primary walls’ corners and also at the locations of cross walls has a significant effect on both the lateral wall deformations and the neighboring soil vertical settlement.


1976 ◽  
Vol 98 (4) ◽  
pp. 592-606 ◽  
Author(s):  
David Japikse

Progress achieved in numerical analysis during the past decade now permits the turbo-machinery designer to carry out a wide variety of inviscid, steady flow, two-dimensional calculations for compressible sybsonic and transonic flow fields, including some strongly diffusing flows. Three-dimensional (including viscosity) calculations are under development and should find wide spread use as analysis tools during the next decade. This review offers an introduction to recent advances in numerical turbomachinery design methods guided by the author’s design usage of several of the techniques reported.


Author(s):  
Spyros A. Karamanos ◽  
Charis Eleftheriadis

The present paper examines the denting deformation of offshore pipelines and tubular members (D/t≤50) subjected to lateral (transverse) quasi-static loading in the presence of uniform external pressure. Particular emphasis is given on pressure effects on the ultimate lateral load of tubes and on their energy absorption capacity. Pipe segments are modeled with shell finite elements, accounting for geometric and material nonlinearities, and give very good predictions compared with test data from non-pressurized pipes. Lateral loading between two rigid plates, a two-dimensional case, is examined first. Three-dimensional case, are also analyzed, where the load is applied either through a pair of opposite wedge-shaped denting tools or a single spherical denting tool. Load-deflection curves for different levels of external pressure are presented, which indicate that pressure has significant influence on pipe response and strength. Finally, simplified analytical models are proposed for the two-dimensional and three-dimensional load configurations, which yield closed-form expressions, compare fairly well with the finite element results and illustrate some important features of pipeline response in a clear and elegant manner.


1977 ◽  
Vol 99 (4) ◽  
pp. 828-834 ◽  
Author(s):  
J. A. Kirk ◽  
D. K. Anand ◽  
C. McKindra

Matrix geometry techniques are applied to predicting three-dimensional cutting forces. In the present model a specific cutting plane is located and two-dimensional metal cutting theory is applied. Force predictions in this plane are then matrix transformed to three orthogonal forces acting on the cutting tool. Experimental results show the matrix model accurately predicts three-dimensional cutting forces in turning of long slender workpieces. Experimental results are also compared to other analytical models described in the literature.


2017 ◽  
Vol 24 (s3) ◽  
pp. 4-11 ◽  
Author(s):  
Jie Zhao ◽  
Lingyun Bao ◽  
Guixuan Wang

Abstract In an artificial island construction project based on the large-scale marine reclamation land, the soil settlement is a key to affect the late safe operation of the whole field. To analyze the factors of the soil settlement in a marine reclamation project, the SEM method in the soil micro-structural analysis method is used to test and study six soil samples such as the representative silt, mucky silty clay, silty clay and clay in the area. The structural characteristics that affect the soil settlement are obtained by observing the SEM charts at different depths. By combining numerical calculation method of Terzaghi’s one-dimensional and Biot’s two-dimensional consolidation theory, the one-dimensional and two-dimensional creep models are established and the numerical calculation results of two consolidation theories are compared in order to predict the maximum settlement of the soils 100 years after completion. The analysis results indicate that the micro-structural characteristics are the essential factor to affect the settlement in this area. Based on numerical analysis of one-dimensional and two-dimensional settlement, the settlement law and trend obtained by two numerical analysis method is similar. The analysis of this paper can provide reference and guidance to the project related to the marine reclamation land.


2013 ◽  
Vol 27 (6) ◽  
pp. 2915-2922 ◽  
Author(s):  
Yesica E. Alvarez ◽  
Brian M. Moreno ◽  
Michael T. Klein ◽  
Justin K. Watson ◽  
Fidel Castro-Marcano ◽  
...  

Author(s):  
Gillian Leplat ◽  
Emmanuel Laroche ◽  
Philippe Reulet ◽  
Pierre Millan

A two-dimensional numerical analysis of a laminar natural convection flow within an air-filled enclosure is proposed in this paper from an unstable configuration previously studied experimentally. The flow is driven by a heated square-section cylinder located at the center of a square-section enclosure. Instabilities are observed for an aspect ratio (height of the cylinder over the height of the cavity) of 0.4 and cause the flow to turn into a three-dimensional and unsteady regime characterized by a symmetry breaking and large scale high amplitude flappings around the cylinder. The multi-physic computational software CEDRE, developed at the ONERA, is used to study this unstable behavior and a time-dependent compressible flow solver is used to perform the two-dimensional simulations under the low Mach number approximation, corresponding to the mid-depth cross-section of the enclosure from the experimental configuration. The first results on the investigation of the first unstable modes confirm the onset of the instabilities at the Rayleigh number of the experiment with asymmetrical motions of the fluid around the cylinder. Further analyses highlight the critical Rayleigh number that defines the instability threshold of the first bifurcation which origin and nature could have been identified. Finally, joint fluid-solid simulations are performed to determine more precisely the role of boundary conditions in the onset of instabilities.


Author(s):  
Chul-hee Jo ◽  
Kang-hee Lee ◽  
Yu-ho Rho ◽  
Do-youb Kim

Recently, large scale tidal devices have been deployed with a maximum rotor diameter of 20m. These devices impose significant loading on supporting structures. The supporting structure for tidal current power device is under dynamic loadings caused by environmental loadings. Not only the environmental loadings but also the rotating turbine creates dynamic loading as well. The rotating turbine is obviously and continuously deformed for various incoming flow velocities. In many cases, a pile fixed foundation is used to secure the structure. In this study, the commonly used pile fixed type is applied with three blade turbine. A numerical analysis of the hydro-forces from a rotating tidal current turbine to a tower was conducted to determine the deformation distribution along the pile tower. The FSI analysis technique is used in the study.


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