Program Sketching Using Lifted Analysis for Numerical Program Families

2021 ◽  
pp. 95-112
Author(s):  
Aleksandar S. Dimovski ◽  
Sven Apel ◽  
Axel Legay
Keyword(s):  
Numerical Program

Making numerical program analysis fast

2015 ◽  
Vol 50 (6) ◽  
pp. 303-313 ◽  
Author(s):  
Gagandeep Singh ◽  
Markus Püschel ◽  
Martin Vechev
Keyword(s):  
Program Analysis ◽  
Numerical Program

scholarly journals Numerical Implementation of a Hydro-Mechanical Coupling Constitutive Model for Unsaturated Soil Considering the Effect of Micro-Pore Structure

2021 ◽  
Vol 11 (12) ◽  
pp. 5368
Author(s):  
Guoqing Cai ◽  
Bowen Han ◽  
Mengzi Li ◽  
Kenan Di ◽  
Yi Liu ◽  
...  
Keyword(s):  
Constitutive Model ◽  
Mechanical Behavior ◽  
Pore Structure ◽  
Unsaturated Soil ◽  
Fortran Program ◽  
Numerical Implementation ◽  
Numerical Application ◽  
Integration Algorithm ◽  
Mechanical Coupling ◽  
Numerical Program

An unsaturated soil constitutive model considering the influence of microscopic pore structure can more accurately describe the hydraulic–mechanical behavior of unsaturated soil, but its numerical implementation is more complicated. Based on the fully implicit Euler backward integration algorithm, the ABAQUS software is used to develop the established hydro-mechanical coupling constitutive model for unsaturated soil, considering the influence of micro-pore structure, and a new User-defined Material Mechanical Behavior (UMAT) subroutine is established to realize the numerical application of the proposed model. The developed numerical program is used to simulate the drying/wetting cycle process of the standard triaxial specimen. The simulation results are basically consistent with those calculated by the Fortran program, which verifies the rationality of the developed numerical program.

Ribbing Instability Analysis of Forward Roll Coating

2009 ◽  
Vol 25 (2) ◽  
pp. 167-175
Author(s):  
K. N. Lie ◽  
Y. M. Chiu ◽  
J. Y. Jang
Keyword(s):  
Surface Coating ◽  
Velocity Ratio ◽  
Rolling Process ◽  
Linear Stability Theory ◽  
Wave Number ◽  
Roll Coating ◽  
Critical Capillary Number ◽  
Roll Velocity ◽  
Forward Roll Coating ◽  
Numerical Program

AbstractThe ribbing instability of forward roll coating is analyzed numerically by linear stability theory. The velocity ratio of two rolls is fixed to be 1/4 for practical surface coating processes. The base flows through the gap between two rolls are solved by use of powerful CFD-RC software package. A numerical program is developed to solve the ribbing instability for the package is not capable of solving the eigenvalue problem of ribbing instability. The effects of the gap between two rolls, flow viscosity, surface tension and average roll velocity on ribbing are investigated. The criterion of ribbing instability is measured in terms of critical capillary number and critical wave number. The results show that the surface coating becomes stable as the gap increases or as the flow viscosity decreases and that the surface coating is more stable to the ribbing of a higher wave number than to the ribbing of a lower wave number. The effect of average roll velocity is not determinant to the ribbing instability. There are optimum and dangerous velocities for each setup of rolling process.

Analysis of structures of flat planting machines

2021 ◽  
Vol 13 (1) ◽  
pp. 140-148
Author(s):  
Andrіі Slabkyі ◽  
◽  
Olexandr Manzhilevskyy ◽  
Olexandr Polishchuk ◽  
◽  
...  
Keyword(s):  
Cutting Tool ◽  
Relative Movement ◽  
Statistical Parameters ◽  
Abrasive Finishing ◽  
Wide Range ◽  
Uneven Wear ◽  
Lapping Machine ◽  
Numerical Program ◽  
Hydraulic Pulse

One of the methods of material processing is considered, which allows to obtain high geometric accuracy and low surface roughness of parts, namely their abrasive finishing. The high quality of machining of parts in this way is due to the use of coordinated relative movement of the workpiece and the cutting tool. According to the kinematic features, most lapping machines can be divided into two groups: machines with oscillating working motion and machines with rotating lapping motion. The machines of the first group are more common due to the simplicity of their design and versatility. However, the possibility of their use is limited by the size range of the workpieces and uneven wear of the cutting tool and, as a consequence, the uneven surface treatment of the part. The machines of the second group are considered the most versatile, as they allow processing a wide range of parts, varying in shape and size, but they are also not without such a disadvantage as uneven wear of the cutting tool with all the corresponding consequences. Improving the efficiency of abrasive finishing by complicating the trajectory of the relative movement of the tool and the part, ie the formation of a unique mutual working movement of the lapping and the movement of the workpiece, is one of the most common areas. The main disadvantage of equipment that provides processing of parts on this principle is, in most cases, limited regulation of the operating parameters of the cutting process, so this area remains promising and has broad prospects for development. The constructive scheme of the hydraulic-pulse flat-lapping machine offered in work thanks to a combination of advantages of the hydraulic-pulse drive with use of numerical program control will allow to provide unique mutual multi-movement of preparation and the lapping tool with a possibility of adjustment of its parameters in the course of processing. Purposeful choice of the shape and density of the trajectory of the working movement of the tool will form a micro relief of the treated surface with the necessary statistical parameters and low roughness.

scholarly journals Features of technological basing in machining parts on CNC machines

2018 ◽  
Vol 224 ◽  
pp. 01078
Author(s):  
Nicolay V. Nosov ◽  
Andrey A. Cherepashkov
Keyword(s):  
Computer Aided Design ◽  
Complex Shape ◽  
Electronic Measuring ◽  
Cnc Machines ◽  
Control Programs ◽  
Integrated Technique ◽  
Aided Design ◽  
And Control ◽  
Numerical Program ◽  
Numerical Program Control

The article discusses the problems of computer aided design and technological preparation of production of complex shape parts on machines with numerical program control. An integrated technique for designing processes and control programs for CNC machines is proposed and described, using the technique of software-based referencing and modern electronic measuring tools.

scholarly journals Decreasing Mining Losses for the Room and Pillar Method by Replacing the Inter-Room Pillars by the Construction of Wooden Cribs Filled with Waste Rocks

Energies ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3564 ◽  
Author(s):  
Krzysztof Skrzypkowski
Keyword(s):  
Underground Mining ◽  
Second Stage ◽  
Ore Body ◽  
Strength Tests ◽  
Waste Rocks ◽  
Rock Pillars ◽  
First Time ◽  
Numerical Program ◽  
Vertical Deformations ◽  
Maximal Capacity

The article presents methods of securing mining excavations using wooden cribs. For the underground room and pillar method used to excavate zinc and lead ore body in the Olkusz-Pomorzany mine in Poland, model tests for the replacement of rock pillars by wooden cribs are presented. In the first stage of research, the results of laboratory strength tests carried out on models of four-point, six-point and eight-point cribs made of wooden beech beams at a 1:28 scale arranged horizontally were determined. For the first time, a concave round notch connection was used to connect the beams of the wooden cribs. The maximal capacity of cribs consisting only of beams and filled with waste rocks taken from underground mining excavations was determined. In addition, the vertical deformations of the cribs at maximal loading force and their specific deformations are presented. Additionally, on the basis of load-displacement characteristics, the range in variability of the stiffness of empty cribs and those filled with waste rocks was calculated as a function of their compressibility. In the second stage of research, the room and pillar method was designed in the Phase2 numerical program. The aim of the study was to determine the stresses in the inter-room pillars. Based on the results of laboratory and numerical tests, a factor of safety was determined, indicating that it is possible to reduce mining losses while maintaining the safe exploitation conditions of the ore body.

CFD-Tool for Thermal-Hydraulics Pressurised Thermal Shock Analysis: Qualification of the Code_Saturne

2002 ◽  
Author(s):  
A. Martin ◽  
S. Bellet
Keyword(s):  
Thermal Shock ◽  
Cold Water ◽  
Life Time ◽  
Test Case ◽  
Fluid Temperature ◽  
Thermal Hydraulics ◽  
Numerical Tools ◽  
Physical Phenomena ◽  
Numerical Program ◽  
Reactor Pressure

This paper explains the numerical program concerning the new thermalhydraulic Code_Saturne qualification for Safety Injection studies. Within the frame of the plant life time project, an analysis has shown that the most severe loading conditions are generated by a pressurised injection of cold water in the downcomer of a Reactor Pressure Vessel. For this kind of transients, a thermal hydraulics study has to be carried out in order to better adjust the accurate distribution of the fluid temperature in the downcomer. For that, the numerical tools have to be able to simulate the physical phenomena present during the Pressurised Thermal Shock. (PTS). For this qualification task, we have investigated one configuration related to an injection of cold water particularly in cold leg but also in a downcomer. One experiment test case has been studied and this paper gives a comparison between experiment and numerical results in terms of temperature field.

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