6 resultados para Experimental data

em AMS Tesi di Laurea - Alm@DL - Università di Bologna


Relevância:

100.00% 100.00%

Publicador:

Resumo:

This thesis selects concrete, steel and their relation as research subjects, mainly commentary and discusses the property changes of steel and concrete materials under and after high temperature.The differences and comparisons of reasearch methods and ways between different researchers and different papers,particularly for chinese researches and chinese papers,and partly for comparison between chinese papers methods and Euro-Amercian papers methods about Fire Resistance Behavior of Reinforced Concrete will be summarized and analyzed.The researches on fire-resistance behavior of reinforced concrete become more and more important all over the world. And I would find differences between Chinese researches results, between Chinese researches results and other countries researches results.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Network Theory is a prolific and lively field, especially when it approaches Biology. New concepts from this theory find application in areas where extensive datasets are already available for analysis, without the need to invest money to collect them. The only tools that are necessary to accomplish an analysis are easily accessible: a computing machine and a good algorithm. As these two tools progress, thanks to technology advancement and human efforts, wider and wider datasets can be analysed. The aim of this paper is twofold. Firstly, to provide an overview of one of these concepts, which originates at the meeting point between Network Theory and Statistical Mechanics: the entropy of a network ensemble. This quantity has been described from different angles in the literature. Our approach tries to be a synthesis of the different points of view. The second part of the work is devoted to presenting a parallel algorithm that can evaluate this quantity over an extensive dataset. Eventually, the algorithm will also be used to analyse high-throughput data coming from biology.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Over the past twenty years, new technologies have required an increasing use of mathematical models in order to understand better the structural behavior: finite element method is the one mostly used. However, the reliability of this method applied to different situations has to be tried each time. Since it is not possible to completely model the reality, different hypothesis must be done: these are the main problems of FE modeling. The following work deals with this problem and tries to figure out a way to identify some of the unknown main parameters of a structure. This main research focuses on a particular path of study and development, but the same concepts can be applied to other objects of research. The main purpose of this work is the identification of unknown boundary conditions of a bridge pier using the data acquired experimentally with field tests and a FEM modal updating process. This work doesn’t want to be new, neither innovative. A lot of work has been done during the past years on this main problem and many solutions have been shown and published. This thesis just want to rework some of the main aspects of the structural optimization process, using a real structure as fitting model.

Relevância:

70.00% 70.00%

Publicador:

Resumo:

Turbulent energy dissipation is presented in the theoretical context of the famous Kolmogorov theory, formulated in 1941. Some remarks and comments about this theory help the reader understand the approach to turbulence study, as well as give some basic insights to the problem. A clear distinction is made amongst dissipation, pseudo-dissipation and dissipation surrogates. Dissipation regulates how turbulent kinetic energy in a flow gets transformed into internal energy, which makes this quantity a fundamental characteristic to investigate in order to enhance our understanding of turbulence. The dissertation focuses on experimental investigation of the pseudo-dissipation. Indeed this quantity is difficult to measure as it requires the knowledge of all the possible derivatives of the three dimensional velocity field. Once considering an hot-wire technique to measure dissipation we need to deal with surrogates of dissipation, since not all the terms can be measured. The analysis of surrogates is the main topic of this work. In particular two flows, the turbulent channel and the turbulent jet, are considered. These canonic flows, introduced in a brief fashion, are often used as a benchmark for CFD solvers and experimental equipment due to their simple structure. Observations made in the canonic flows are often transferable to more complicated and interesting cases, with many industrial applications. The main tools of investigation are DNS simulations and experimental measures. DNS data are used as a benchmark for the experimental results since all the components of dissipation are known within the numerical simulation. The results of some DNS were already available at the start of this thesis, so the main work consisted in reading and processing the data. Experiments were carried out by means of hot-wire anemometry, described in detail on a theoretical and practical level. The study of DNS data of a turbulent channel at Re=298 reveals that the traditional surrogate can be improved Consequently two new surrogates are proposed and analysed, based on terms of the velocity gradient that are easy to measure experimentally. We manage to find a formulation that improves the accuracy of surrogates by an order of magnitude. For the jet flow results from a DNS at Re=1600 of a temporal jet, and results from our experimental facility CAT at Re=70000, are compared to validate the experiment. It is found that the ratio between components of the dissipation differs between DNS and experimental data. Possible errors in both sets of data are discussed, and some ways to improve the data are proposed.

Relevância:

70.00% 70.00%

Publicador:

Resumo:

This paperwork compares the a numerical validation of the finite element model (FEM) with respect the experimental tests of a new generation wind turbine blade designed by TPI Composites Inc. called BSDS (Blade System Design Study). The research is focused on the analysis by finite element (FE) of the BSDS blade and its comparison with respect the experimental data from static and dynamic investigations. The goal of the research is to create a general procedure which is based on a finite element model and will be used to create an accurate digital copy for any kind of blade. The blade prototype was created in SolidWorks and the blade of Sandia National Laboratories Blade System Design Study was accurately reproduced. At a later stage the SolidWorks model was imported in Ansys Mechanical APDL where the shell geometry was created and modal, static and fatigue analysis were carried out. The outcomes of the FEM analysis were compared with the real test on the BSDS blade at Clarkson University laboratory carried out by a new procedures called Blade Test Facility that includes different methods for both the static and dynamic test of the wind turbine blade. The outcomes from the FEM analysis reproduce the real behavior of the blade subjected to static loads in a very satisfying way. A most detailed study about the material properties could improve the accuracy of the analysis.

Relevância:

70.00% 70.00%

Publicador:

Resumo:

The new knee test rig developed in University of Bologna used pneumatic cylinder as actuator system. Specific characterization and modelling about the pneumatic cylinder and the related devices are needed in better controlling the test rig. In this thesis, an experimental environment for the related device is set up with data acquisition system using Real-time Windows Target, Simulink, MatLab. Based on the experimental data, a fitted model for the pneumatic cylinder friction is found.