Determination of optimum diameter of a welded stiffened cylindrical shell

In this article, the investigation of a press machine with 30 tons of pressing weight is presented. The beam of this machine is an I-beam, which has an open cross-section. It is known that this version of cross-section is sensitive to torsional stress. The stress from warping torsion is normal stress, so the opened cross-section is more sensitive to this type of stress. The bimoment that causes normal stress can also be very high, so dealing with this stress is very important.

“…For this procedure, the Microsoft Excel Solver was used, and within it, the Nonlinear General Reduced Gradient method. The formulae for the optimization are the follows [1], [7], [8]:…”

Section: Optimizationmentioning

confidence: 99%

Investigation of the Warping Torsion of a Press Machine

Erdős

Jármai

2020

“…Welded joints are extensively used in oil and natural gas pipeline, power plant and pressure vessels. Dissimilar pipe welds are commonly found in various industrial applications due to both technical and economic reasons [1]. One of the significant problems in pipe welded structures is residual stresses caused by shrinkage of the material after the welding process.…”

Section: Introductionmentioning

confidence: 99%

Prediction and numerical simulation of residual stress in multi-pass pipe welds

Alhafadhi

Krállics

2021

A numerical simulation procedure is presented to predict residual stress states in multi-pass welds in oil transportation pipes. In this paper, a two-dimensional thermo-mechanical finite element model is used to calculate the temperature distribution, hardness, and the distribution of residual stresses during multi-pass welding of pipes of dissimilar metals and varying thicknesses. In this model, the temperature dependence of the thermal and mechanical properties of the material was considered. The present model was validated using the hardness measurement. Good agreement was found between the measurement and the numerical simulation results. The simulated result shows that the two-dimensional model can be effectively used to simulate the hardness test and predict the residual stress in the pipe weld. The simulation results and measurements suggest that the model with moving heat source can obtain a good prediction of residual welding stress. Both the two-dimensional and the three-dimensional modeling can be used to estimate the residual stresses in different weld regions and help saving time.

“…Even though various efforts have been made in the past to express the deflection of panels from experimental aspects and measurements of actual structures, it may be said that there are few investigations from the theoretical point of view. For higher heat, the behavior of the steel is even more complicated [5,6].…”

Section: Introductionmentioning

confidence: 99%

Optimization of asymmetric I-beams for minimum welding shrinkage

Jármai

Petrik

2021

A calculation system has been developed to determine the optimum dimensions of asymmetric I-beams for minimum shrinkage. The objective function is the minimum mass; the unknowns are the I-beam dimensions; the constraints are the stress, local buckling, and deflection. Different steel grades have been considered (235, 355, 460 (MPa) yield stress) and other aluminum alloys (90, 155, 230 (MPa) yield stress). The material, the span length, the loading, and the applied heat input have been changed. It is shown, that using optimum design; the welding shrinkage can be reduced with prebending and can save material cost as well.