| ATTRIBUTE | VALUE |
|---|
| type | A |
| database id | 5970 |
| title | Hypoplastic modelling of pre-failure behaviour of sand against experimental data |
| authors | Głębowicz K. |
| pages | 31 — 47 |
| full text link | http://www.ibwpan.gda.pl/storage/app/media/ahem/ahem53str031.pdf |
| keywords | hypoplasticity, constitutive equation, sand, deformation, anisotropy |
| affiliations | - Institute of Hydro-Engineering, Polish Academy of Sciences, ul. Kościerska 7, 80-328 Gdańsk, Poland, e-mail: dexter@ibwpan.gda.pl
|
| abstracts | The aim of this article is to compare experimentally determined strains of sand with theoretical calculations made on the base of the theory of hypoplasticity. During the study "Skarpa" sand was examined in the triaxial apparatus with local measurement of vertical and lateral strains. Results obtained were used to calibrate 8-parameter von Wolffersdorff model. Subsequently, the behaviour of loose and dense sandy samples subjected to different stress paths was predicted. |
| attributes | [reviewed] [scientific] |
| language | en |
| points | 6 |
| ATTRIBUTE | VALUE |
|---|
| type | A |
| database id | 5969 |
| title | Comprehensive circumscribing of non-linearity cases of a water supply system with smooth flow control |
| authors | Ryszard Orłowski |
| pages | 7 — 30 |
| full text link | http://www.ibwpan.gda.pl/storage/app/media/ahem/ahem53str007.pdf |
| keywords | flow reducing valve, non-linearity of the system, pressure reducing valve, steady flows, variable frequency drives, water supply system |
| affiliations | - Gdańsk University of Technology, Faculty of Civil and Environmental Engineering, ul. G. Narutowicza 11/12, 80-952 Gdańsk, Poland, e-mail: rorl@poczta.onet.pl, rorl@pg.gda.pl
|
| abstracts | The descriptions found in the literature, of cases of even relatively strong non-linearity of the water supply systems, as well as their mathematical treatment, are rare and incomplete. They refer mainly to the non-linearity with respect to smooth flow control components (for instance, to the operation of pressure reducing valves (PRV), flow reducing valves (FRV) and pumps with motors equipped with smooth rotational speed control – variable frequency drives (VFD)). The article proposes a formally correct method of a comprehensive solution of the above non-linearity cases based on successive simulations with some dynamic analysis of the sensitivity of the system to the operation of the smooth control components mentioned. An appropriate algorithm controlling the effectiveness of the calculations secures correct description of the behaviour of the system for an arbitrary, in practice, method of control of flows, even if all the proposed smooth control methods are used simultaneously. The effects of the use of the solutions presented in mathematical modelling are illustrated by selected results of simulation carried out for an existing water supply system. |
| attributes | [reviewed] [scientific] |
| language | en |
| ATTRIBUTE | VALUE |
|---|
| type | A |
| database id | 5972 |
| title | Deformation measurements in granular bodies using a particle image velocimetry technique |
| authors | Cezary Słomiński, Maciej Niedostatkiewicz, Jacek Tejchman |
| pages | 71 — 94 |
| full text link | http://www.ibwpan.gda.pl/storage/app/media/ahem/ahem53str071.pdf |
| keywords | PIV, pull-out test, sand, silo flow, strain, wall roughness |
| affiliations | - Karlsruhe University, Institute for Soil and Rock Mechanics, Karlsruhe, Germany
- Gdańsk University of Technology, Faculty of Civil and Environmental Engineering, ul. G. Narutowicza 11/12, 80-952 Gdańsk, Poland, e-mail: tejchmk@pg.gda.pl
|
| abstracts | The paper presents results of strain measurements in cohesionless sand in two different boundary value problems, namely quasi-static pull-out test of a steel wall and confined granular flow in a rectangular model silo using a non-destructive method called Particle Image Velocimetry (PIV) which is a technique for measuring surface displacements from digital images. Advantages and disadvantages of the method are outlined. |
| attributes | [reviewed] [scientific] |
| language | en |
| ATTRIBUTE | VALUE |
|---|
| type | A |
| database id | 5971 |
| title | Application of Potential Theory in Calculating Wave-Induced Vertical Forces on horizontal cylinders near a plane boundary |
| authors | Marcinkowski T., Wilde P. |
| pages | 49 — 69 |
| full text link | http://www.ibwpan.gda.pl/storage/app/media/ahem/ahem53str049.pdf |
| keywords | hydrodynamic forces, underwater pipeline, potential theory, diffraction theory, curvilinear coordinates |
| affiliations | - Gdańsk University of Technology, Faculty of Civil and Environmental Engineering, ul. G. Narutowicza 11/12, 80-952 Gdańsk, Poland, e-mail: tmar@pg.gda.pl
- Polish Academy of Sciences, Institute of Hydro-Engineering (IBW PAN), ul. Kościerska 7, 80-328 Gdańsk, Poland
|
| abstracts | Hydrodynamic forces acting on a horizontal cylinder located in the vicinity of the bottom are analyzed by a diffraction theory which solves the problem in terms of a velocity potential. The cylinder is assumed to be rigidly anchored to the bottom at a sufficient depth, so that it has no influence on the surface profile. The potential function φ is defined as the sum of the incident wave velocity potential φw and the scattered wave velocity potential φa. The results of measurements of wave-induced pressures and forces on a horizontal cylinder located close to the bottom are compared with the theoretical solution based on the potential theory for incompressible, perfect fluid and ideal boundary conditions at the bottom and the surface of the cylinder. The experiments were carried out in the Large Wave Channel in Hannover with a cylinder of 0.8 m diameter. Thus the results are in a scale which corresponds to real pipelines. The analysis shows that the potential theory explains the components with double frequency of the wave in pressures and vertical forces as far as the amplitudes are concerned. In the experiments, the Keulegan-Carpenter number is rather low and the inertia hydrodynamic forces on the cylinder are dominant. It seems that the observed phase shift between the force component and the wave results from the energy dissipation which is not considered in the theoretical solution. |
| attributes | [reviewed] [scientific] |
| language | en |
| points | 6 |