Laser micro-welding of aluminum alloys: experimental studies and numerical modeling

2010 ◽  
Vol 50 (1-4) ◽  
pp. 207-215 ◽  
Author(s):  
Magnus Rohde ◽  
Christine Markert ◽  
Wilhelm Pfleging
1993 ◽  
Author(s):  
Sten Madsen ◽  
Michael S. Patterson ◽  
Brian C. Wilson ◽  
Satish M. Jaywant ◽  
Andreas Othonos

Author(s):  
Vladislav Ponomarev ◽  
Galina Kashevarova

The article considers a promising technology for self-shaping glued wooden elements of curved forms. This method is based on rheological processes occurring in wood, such as dehumidification and swelling of wood and its anisotropic properties. To predict the final curved shape of the wooden structure, the authors analyzed existing rheological models of wood and concluded that the rheological model proposed by European researchers includes the most complete list of factors that affect the process of deformation of wood: elastic and plastic deformation, drying and swelling of wood, deformation of viscous-elastic creep and mechanical sorption deformation. Based on the results of experimental studies and numerical modeling of the change in the curvature of glued wooden elements, which were made by European researchers, it was found that the proposed rheological model of wood needs to be clarified, namely, the correction of hygro-expansion coefficients depending on the moisture content of wood. A further direction of the authors’ research will be aimed at conducting model experiments to determine the hygro-expansion coefficients of different grades of wood depending on the thickness of the wooden elements and the orientation of the layers in the glued structure.


2021 ◽  
Vol 4 (1) ◽  
pp. 193-198
Author(s):  
Vladimir F. Raputa ◽  
Ruslana A. Amikishieva ◽  
Tatyana V. Yaroslavtseva

The numerical analysis of mercury pollution in the vicinity of the “Usoliekhimprom" industrial site and a territory of Usolye-Sibirskoye was held. The main centers of atmospheric influx of mercury vapor, which are located in the area of the sludge storage and the former mercury electrolysis workshop, were determined by the results of the soil survey. Asymptotic descriptions of the processes of transfer of light impurities from ground-based sources, taking into account the relative position of foci and observation points, were proposed. A reconstruction model of concentration fields over a long period of time for the dominant sources of plant was developed. The model was tested on biomonitoring data for 2019. Quite satisfactory agreement between the data of experimental studies of the content of mercury in poplar leaves with the results of numerical modeling was obtained. The ratios of contributions to pollution from different objects of the enterprise were calculated. Recommendations on the use of the reconstruction model to control rehabilitation measures at the Usoliekhimprom industrial site, which are currently being carried out, have been proposed.


RSC Advances ◽  
2016 ◽  
Vol 6 (21) ◽  
pp. 17196-17203 ◽  
Author(s):  
Zheng Zeng ◽  
Madu N. Mendis ◽  
David H. Waldeck ◽  
Jianjun Wei

A semi-analytical analysis of a nanoledged plasmonic device for optimal optical performance, validated with numerical modeling and experimental studies.


Author(s):  
S.Yu. Ploskov

Landing parachute systems are among the most demanded samples of parachute equipment. The purpose of the study was to find new principles for developing parachutes with increased stability according to the analysis of the results of numerical and experimental studies of canopies of various shapes. The paper proposes to supplement a traditional definition of the stability of a parachute system with the obligatory consideration of the system’s ability to maintain a given trajectory of movement with a neutral canopy, regardless of the change in the payload mass. It is the expanded concept of stability that is taken as the basis of the modern approach to the design of foreign landing parachute systems. The study substantiates the main criteria for choosing the optimal cutting shape for parachute systems of increased stability of various types at the stage of preliminary design. The results of numerical modeling of canopies are presented: quarter-spherical, hemispherical, polyconic canopies and a T-11 type parachute canopy. Based on the analysis of these results, the study was first to propose a hypothesis that a decrease in the intensity of vortex formation in the wake leads to an increase in the stability of the parachute descent. The results of numerical modeling of canopies of various shapes, as well as experimental studies of a model polyconic parachute, which prove the correctness of the proposed hypothesis, are presented.


2004 ◽  
Vol 127 (3) ◽  
pp. 612-621 ◽  
Author(s):  
Aniruddha Khadke ◽  
Somnath Ghosh ◽  
Ming Li

This work combines experimental studies with finite element simulations to develop a reliable numerical model for the simulation of shearing process in aluminum alloys. The critical concern with respect to product quality in this important process is burr formation. Numerical simulations are aimed at understanding the role of process variables on burr formation and for recommending process design parameters. The commercial code ABAQUS-Explicit with the arbitrary Lagrangian-Eulerian kinematic description is used in this study for numerical simulations. An elastic-plastic constitutive model with experimentally validated damage models are incorporated through the user subroutine VUMAT in ABAQUS, for modeling deformation and ductile fracture in the material. Macroscopic experiments with microscopic observations are conducted to characterize the material and to calibrate the constitutive and damage models. Parametric study is done to probe the effect of process parameters and finally, a genetic algorithm (GA) based design method is used to determine process parameters for minimum burr formation.


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