Temperature Control of a Solar Furnace with Exact Linearization and Off-Line Identification
The ability to predict the behavior of materials is crucial in several industries due to safety aspects, such as in high temperature furnaces for the production of glass, in the nuclear energy industry or in the high concentrated thermal solar systems. Solar furnaces use concentrated solar radiation that can be used to perform material stress tests with high temperatures. These devices have nonlinear dynamics that are caused by the actuator, the shutter, and by the interaction between the solar energy and the properties of the material. The contribution of this paper consists in the design of a controller for practical use based on the exact linearization method with off-line identification. The aim is to improve the controller performance to track the temperature profile. In this context it is assumed that the thermodynamic properties of the sample material to be tested are unknown.
Predictive adaptive temperature control in a solar furnace for material stress tests
This paper explores the adaptive predictive Musmar algorithm to control the temperature of material samples in a solar furnace. Solar furnaces are devices that are powered by concentrated solar energy and are used in material stress applications. Solar furnaces are characterized by having a nonlinear dynamics, the nonlinear effect between the incident energy and the temperature of the sample, the nonlinear relation between the positioning of the shutter and the incident power applied on the sample, the interaction between the shutter dynamics and the temperature dynamics of the sample and the presence of fast perturbations on sunlight induced by clouds. This work is being developed in the framework of the SFERA project, to automate material stress experiments in solar furnaces of the Odeillo Processes Materials and Solar Energy Laboratory, located at the Oriental Pyrenees in the South of France.
Evaluation of buckling load and dynamic performance of steel shear wall retrofitted with strips made of shape memory alloy
One of the most imperfections of the steel shear wall is out of plane displacements that cause severe damage in both structural and non-structural elements. In this paper, the effects of shape-memory alloys on steel shear walls are investigated. First, a numerical analysis using the finite element method in ABAQUS software has been carried out according to an experimental test. The results of the numerical analysis have been verified with experimental results. Next, shape-memory alloy fibers have been added vertically and horizontally to various parts of the steel shear wall. The results show that retrofitting with the shape-memory alloy reduces the out-of-plane displacement of the steel shear wall under both cyclic and seismic loadings. Besides, the buckling load in the steel shear wall increases when it is retrofitted with the shape-memory alloy. Also, the total out-of-plane movement (accumulated absolute displacements) of the steel shear wall and non-structural damage are controlled by the characteristic of a shape-memory alloy material called “super-elastic”.