Optimizing Tack Welding Fabrication Procedures Using Numerical Finite Element Models

2010 ◽  
Vol 26 (02) ◽  
pp. 117-134 ◽  
Author(s):  
D. Camilleri ◽  
T.G.F. Gray ◽  
N. McPherson
Keyword(s):  
Finite Element ◽  
Parametric Study ◽  
Plane Deformation ◽  
Finite Element Models ◽  
Plate Structures ◽  
Seam Weld ◽  
Out Of Plane ◽  
Numerical Finite Element

The aim of this study was to investigate the influence of different tack welding fabrication procedures on the final deformations of seam welded plate structures. In this study the length of the tacks, number of tacks, and position of tacks with respect to the final seam weld are altered, and their sensitivity with respect to out-of-plane deformation is established. A parametric study of these three different procedural variations is performed via finite element models to identify which fabrication procedures would lead to minimal out-of-plane distortion.

Dynamic stiffness formulation for the vibrations of stiffened plate structures with consideration of in-plane deformation

2017 ◽  
Vol 24 (20) ◽  
pp. 4825-4838 ◽  
Author(s):  
Xuewen Yin ◽  
Wenwei Wu ◽  
Kuikui Zhong ◽  
Hui Li
Keyword(s):  
Finite Element ◽  
Dynamic Stiffness ◽  
Plane Deformation ◽  
Element Model ◽  
The Finite Element Method ◽  
Plate Structures ◽  
Beam Elements ◽  
Stiffness Model ◽  
Out Of Plane ◽  
The Relationship

A dynamic stiffness method is presented for the vibrations of plate structures that are reinforced by eccentric stiffeners. The model incorporates both out-of-plane and in-plane deformations of the plates and the stiffeners. Based on the relationship between the forces and displacements along the common edges of the plate or beam elements, the dynamic stiffness formulae for the plate and the beam elements are derived, respectively. The globally assembled dynamic stiffness matrix is then obtained using the finite element method so that the dynamics of built-up stiffened plates can be readily addressed by using the present method. Compared to the conventional finite element model, the dynamic stiffness model can provide very accurate solutions using only one element over each uniform plate and beam member, regardless of its geometry.

scholarly journals Out-of-plane local mechanism analysis with finite element method

2021 ◽  
Vol 8 (1) ◽  
pp. 130-136
Author(s):  
Roberto Spagnuolo
Keyword(s):  
Finite Element ◽  
Masonry Walls ◽  
Finite Element Models ◽  
Mechanism Analysis ◽  
Fem Method ◽  
Local Mechanism ◽  
Out Of Plane ◽  
Smeared Crack ◽  
The Stability ◽  
No Tension Material

Abstract The stability check of masonry structures is a debated problem in Italy that poses serious problems for its extensive use. Indeed, the danger of out of plane collapse of masonry walls, which is one of the more challenging to evaluate, is traditionally addressed not using finite element models (FEM). The power of FEM is not properly used and some simplified method are preferred. In this paper the use of the thrust surface is suggested. This concept allows to to evaluate the eccentricity of the membrane stresses using the FEM method. For this purpose a sophisticated, layered, finite element with a no-tension material is used. To model a no-tension material we used the smeared crack method as it is not mesh-dependent and it is well known since the early ’80 in an ASCE Report [1]. The described element has been implemented by the author in the program Nòlian by Softing.

Strains and Deflections of GFRP Sandwich Panels Due to Uniform Out-of-Plane Pressure

2002 ◽  
Vol 39 (04) ◽  
pp. 223-231
Author(s):  
J. C. Roberts ◽  
M. P. Boyle ◽  
P. D. Wienhold ◽  
E. E. Ward
Keyword(s):  
Finite Element ◽  
Compressive Strain ◽  
Sandwich Panels ◽  
External Pressure ◽  
Woven Fabric ◽  
Core Material ◽  
Finite Element Models ◽  
Strain Gages ◽  
Glass Fiber Reinforced Plastic ◽  
Out Of Plane

Rectangular orthotropic glass fiber reinforced plastic sandwich panels were tested under uniform out-of-plane pressure and the strains and deflections were compared with those from finite-element models of the panels. The panels, with 0.32 cm (0.125 in.) face sheets and a 1.27 cm (0.5 in.)core of either balsa or linear polyvinylchloride foam, were tested in two sizes: 183 × 92 cm (72 × 36 in.) and121 × 92 cm (48 × 36 in.). The sandwich panels were fabricated using the vacuum-assisted resin transfer molding technique. The two short edges of the sandwich panels were clamped, while the two long edges were simply supported. Uniform external pressure was applied using two large water inflatable bladders in series. The deflection and strains were measured using dial gages and strain gages placed at quarter and half points on the surface of the panels. Measurements were made up to a maximum out-of-plane pressure of 0.1 MPa (15psi). A total of six balsa core and six foam core panels were tested. Finite-element models were constructed for the 183-cm-long panel and the121-cm-long panel. Correlation between numerical and experimental strains to deflect the sandwich panel was much better on the top (tensile) side of the panels than on the bottom (compressive)side of the panels, regardless of panel aspect ratio or core material. All sandwich panels exhibited the same compressive strain reversal behavior on the compressive side of the panel. This phenomenon was thought to be due to nonlinearly induced micro-buckling under the strain gages, buckling of the woven fabric, or micro-cracking within the resin.

Axial strength of steel circular hollow section (CHS) X-joints strengthened by flanged larger pipe

2020 ◽  
Vol 47 (3) ◽  
pp. 301-316
Author(s):  
Peter Gerges ◽  
Sameh Gaawan ◽  
Ashraf Osman
Keyword(s):  
Finite Element ◽  
Parametric Study ◽  
Thickness Ratio ◽  
Finite Element Models ◽  
T Joints ◽  
Hollow Section ◽  
Axial Strength ◽  
Structural Joints ◽  
Circular Hollow Section ◽  
Steel Design

In steel design, enhancing the structural joints’ capacity is considered a challenge that faces the designer. This challenge becomes more difficult when it comes to enhancing the capacities of circular hollow section (CHS) joints due to their closed nature that complicates the strengthening process. Recent research related to strengthening T-joints by utilizing two outer hollow ring flanges welded to additional pipe showed that this technique can significantly improve the joints’ strength. In this study, the utilization of this technique is extended for enhancing the axial strength of CHS X-joints. In this regard, a parametric study using finite element models was carried out to investigate the different design aspects that might affect the behavior of strengthened X-joints. The examined parameters included, the ring flange diameter, the stiffening pipe thickness and length for different brace diameter-to-chord diameter ratios and chord diameter to double chord thickness ratio. The results demonstrated that these strengthened X-joints gained significant axial strength that reached up to three times the axial strength of the unstrengthened joints. Guidelines for proper detailing of such strengthening scheme were provided. Finally, an equation that estimates the axial strength of strengthened joints was established based on the achieved results.

Cemented Wellbore Experiments Reveals That Cement Interface Debonding Modeling Overestimate Potential Leakage Rates

2020 ◽  
Author(s):  
Zachary Speer ◽  
Jarrett Wise ◽  
Runar Nygaard ◽  
Geir Hareland ◽  
Eric Ford ◽  
...  
Keyword(s):  
Experimental Data ◽  
Finite Element ◽  
Numerical Models ◽  
Interface Debonding ◽  
Finite Element Models ◽  
Wellbore Integrity ◽  
Cement Interface ◽  
Abandoned Wells ◽  
Numerical Finite Element ◽  
Physical And Chemical

Abstract Leakage pathways may develop in wellbores during construction, production, or during and after plug and abandonment (P&A). These pathways are created due to events and conditions during cementing operations, or because of physical and chemical changes after cementing such as changes in temperature and wellbore pressures, and deterioration of the cement. Common leakage pathways develop inside the cement sheath, or as microannuli along the cement-tubing interface. Numerous evidence exists showing that wellbores leak, but there is no verified method to determine if a well will leak or not. To ensure long term wellbore integrity, leakage risks need to be evaluated for plugged and abandoned wells. To evaluate leakage risks from plugged and abandoned wells, numerical finite element models have been developed and used to investigate leakage scenarios during the life of the well. Currently, little work has been done to verify finite element numerical models with experimental data regarding flowpath size in cement sheaths. The aim of this paper is to model previously published experimental data to determine if the finite element models can accurately predict leakage potentials. Two lengths of cemented annuli were modeled, each with conventional and expanding cement to replicate the Aas et. al. [1] experiments. The numerical results show that the simulated microannuli overestimate flow rate compared to experimental data, indicating that flow path dimensions and/or fluid friction factor does not accurately represent the fluid flow in the experiments.

Forming limit diagrams by including the M–K model in finite element simulation considering the effect of bending

2016 ◽  
Vol 232 (8) ◽  
pp. 625-636 ◽  
Author(s):  
Mostafa Habibi ◽  
Ramin Hashemi ◽  
Ahmad Ghazanfari ◽  
Reza Naghdabadi ◽  
Ahmad Assempour
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Metal Forming ◽  
Forming Limit Diagram ◽  
Element Model ◽  
Forming Limit ◽  
Finite Element Models ◽  
Element Simulation ◽  
Simple Tension ◽  
Out Of Plane

Forming limit diagram is often used as a criterion to predict necking initiation in sheet metal forming processes. In this study, the forming limit diagram was obtained through the inclusion of the Marciniak–Kaczynski model in the Nakazima out-of-plane test finite element model and also a flat model. The effect of bending on the forming limit diagram was investigated numerically and experimentally. Data required for this simulation were determined through a simple tension test in three directions. After comparing the results of the flat and Nakazima finite element models with the experimental results, the forming limit diagram computed by the Nakazima finite element model was more convenient with less than 10% at the lower level of the experimental forming limit diagram.

Ultimate Behavior of Single Shear Bolted Connections with Thin-Walled Aluminum Alloys(6061-T6)

2012 ◽  
Vol 446-449 ◽  
pp. 3441-3445 ◽  
Author(s):  
Tae Soo Kim ◽  
Yong Hyun Jo ◽  
Seung Hun Kim ◽  
Yong Taeg Lee
Keyword(s):  
Finite Element ◽  
Ultimate Strength ◽  
Plane Deformation ◽  
Free Edge ◽  
Fe Analysis ◽  
Test Results ◽  
Bolted Connections ◽  
Element Analysis ◽  
Out Of Plane ◽  
Single Shear

The purpose of this study is to investigate the ultimate behaviors of aluminum alloy bolted connections assembled with four bolts. Specimens for single shear bolted connections were tested and finite element analysis based on this test results was conducted. The validity of finite element(FE) analysis for predicting the structural behaviors such as ultimate strength, fracture mode and curling(out-of-plane deformation) occurrence was verified through the comparisons between test results and FE analysis results. It is known that the curling resulted in sudden strength drop. Moreover, FE models with free edge and restrained out-of-plane deformation for curled specimens are analyzed additionally, therefore, the influence of curling on the ultimate strength; strength reduction ratio is estimated.

Behaviour of hollow concrete masonry walls with one-course bond beams subjected to concentric and eccentric concentrated loading

2003 ◽  
Vol 30 (1) ◽  
pp. 181-190 ◽  
Author(s):  
Junyi Yi ◽  
Nigel G Shrive
Keyword(s):  
Finite Element ◽  
Failure Modes ◽  
Three Dimensional ◽  
Masonry Walls ◽  
Finite Element Models ◽  
Concentrated Load ◽  
Concrete Masonry ◽  
Out Of Plane ◽  
Concentrated Loading ◽  
Concrete Masonry Walls

Three-dimensional finite element models of unreinforced hollow concrete masonry walls with one-course bond beams subjected to concentrated loading have been analyzed. The walls were modelled with different loading plate sizes, different loading locations along the wall (at the midpoint of the wall, at the end of the wall, and between these points), and different out-of-plane eccentricities (e = 0, t/6, and t/3). The hollow block units, mortar, grout, and bond beam blocks in the walls were modelled separately. Both smeared and discrete cracking methods have been utilized for predicting cracking under load. Geometric and material nonlinearities and damage due to progressive cracking were taken into account in the analyses. The predicted failure modes and ultimate capacities of the walls with the concentric concentrated load applied at the midpoint or at the end of the wall compared very well with the experimental results. When the load was between the midpoint and the end of the wall, the predicted ultimate capacity was between those for the load at the midpoint and at the end. The strength of the walls decreases with increasing out-of-plane eccentricities.Key words: finite element models, hollow masonry, smeared and discrete cracking models, concentrated load, loading locations, out-of-plane eccentricities.

Design Support Tool for Prediction of Welding Distortion in Multiply Stiffened Plate Structures: Experimental and Computational Investigation

2005 ◽  
Vol 21 (04) ◽  
pp. 219-234
Author(s):  
Duncan Camilleri ◽  
Tugrul Comlekci ◽  
Thomas G. F. Gray
Keyword(s):  
Large Scale ◽  
Computational Models ◽  
Plane Deformation ◽  
Computational Prediction ◽  
Welding Distortion ◽  
Plate Structures ◽  
Welded Structures ◽  
Welding Sequence ◽  
Out Of Plane ◽  
Welding Processes

Many industries, such as shipbuilding, concerned with the fabrication of fusionwelded plate structures, face increasing challenges to produce lightweight structures. This design requirement is commonly met by using thin-plate, multiply stiffened, welded structures, but severe difficulties and high rectification costs are frequently incurred, related to the evolution of out-of-plane deformations. The overall scope of this study is to improve the applicability of computational prediction of distortion by providing simple and adaptable methodologies, which can be readily validated through experience of application in the industrial context. These methods are designed to be computationally economic and robust, and they are also generic with respect to material properties, welding processes, and thickness. The aim is to provide design engineers with the tools to explore alternative structural and process parameters and hence to find out if the outcomes will be acceptable, prior to embarking on manufacturing operations typical of large-scale welded structures. The validity of the simulations was investigated via full-scale tests where several filletwelded 100 mm × 6 mmstiffeners were attached to 4 m × 1.5 m × 5 mmthick plates, according to different sequences. The computational models were used to optimize the welding scheme with respect to minimum out-of-plane deformation and welding sequence.

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