Thursday, 24 July 2014

THERMAL ANALYSIS

THERMAL ANALYSIS IS A BRANCH OF MATERIALS SCIENCE WHERE THE PROPERTIES OF MATERIALS ARE STUDIED AS THEY CHANGE WITH TEMPERATURE. SEVERAL METHODS ARE COMMONLY USED – THESE ARE DISTINGUISHED FROM ONE ANOTHER BY THE PROPERTY WHICH IS MEASURED:
·         DIELECTRIC THERMAL ANALYSIS (DEA): DIELECTRIC PERMITTIVITY AND LOSS FACTOR
·         DIFFERENTIAL THERMAL ANALYSIS (DTA): TEMPERATURE DIFFERENCE
·         DIFFERENTIAL SCANNING CALORIMETRY (DSC): HEAT DIFFERENCE
·         DILATOMETRY (DIL): VOLUME
·         DYNAMIC MECHANICAL ANALYSIS (DMA) : MECHANICAL STIFFNESS AND DAMPING
·         EVOLVED GAS ANALYSIS (EGA) : GASEOUS DECOMPOSITION PRODUCTS
·         LASER FLASH ANALYSIS (LFA): THERMAL DIFFUSIVITY AND THERMAL CONDUCTIVITY
·         THERMOGRAVIMETRIC ANALYSIS (TGA): MASS
·         THERMOMECHANICAL ANALYSIS (TMA): DIMENSION
·         THERMO-OPTICAL ANALYSIS (TOA): OPTICAL PROPERTIES



SIMULTANEOUS THERMAL ANALYSIS (STA) GENERALLY REFERS TO THE SIMULTANEOUS APPLICATION OF THERMOGRAVIMETRY (TGA) AND DIFFERENTIAL SCANNING CALORIMETRY (DSC) TO ONE AND THE SAME SAMPLE IN A SINGLE INSTRUMENT. THE TEST CONDITIONS ARE PERFECTLY IDENTICAL FOR THE TGA AND DSC SIGNALS (SAME ATMOSPHERE, GAS FLOW RATE, VAPOR PRESSURE OF THE SAMPLE, HEATING RATE, THERMAL CONTACT TO THE SAMPLE CRUCIBLE AND SENSOR, RADIATION EFFECT, ETC.). THE INFORMATION GATHERED CAN EVEN BE ENHANCED BY COUPLING THE STA INSTRUMENT TO AN EVOLVED GAS ANALYZER (EGA) LIKE FOURIER TRANSFORM INFRARED SPECTROSCOPY (FTIR) OR MASS SPECTROMETRY (MS).



OTHER, LESS-COMMON, METHODS MEASURE THE SOUND OR LIGHT EMISSION FROM A SAMPLE, OR THE ELECTRICAL DISCHARGE FROM A DIELECTRIC MATERIAL, OR THE MECHANICAL RELAXATION IN A STRESSED SPECIMEN. THE ESSENCE OF ALL THESE TECHNIQUES IS THAT THE SAMPLE'S RESPONSE IS RECORDED AS A FUNCTION OF TEMPERATURE (AND TIME).
IT IS USUAL TO CONTROL THE TEMPERATURE IN A PREDETERMINED WAY - EITHER BY A CONTINUOUS INCREASE OR DECREASE IN TEMPERATURE AT A CONSTANT RATE (LINEAR HEATING/COOLING) OR BY CARRYING OUT A SERIES OF DETERMINATIONS AT DIFFERENT TEMPERATURES (STEPWISE ISOTHERMAL MEASUREMENTS). MORE ADVANCED TEMPERATURE PROFILES HAVE BEEN DEVELOPED WHICH USE AN OSCILLATING (USUALLY SINE OR SQUARE WAVE) HEATING RATE (MODULATED TEMPERATURE THERMAL ANALYSIS) OR MODIFY THE HEATING RATE IN RESPONSE TO CHANGES IN THE SYSTEM'S PROPERTIES (SAMPLE CONTROLLED THERMAL ANALYSIS).



IN ADDITION TO CONTROLLING THE TEMPERATURE OF THE SAMPLE, IT IS ALSO IMPORTANT TO CONTROL ITS ENVIRONMENT (E.G. ATMOSPHERE). MEASUREMENTS MAY BE CARRIED OUT IN AIR OR UNDER AN INERT GAS (E.G. NITROGEN OR HELIUM). REDUCING OR REACTIVE ATMOSPHERES HAVE ALSO BEEN USED AND MEASUREMENTS ARE EVEN CARRIED OUT WITH THE SAMPLE SURROUNDED BY WATER OR OTHER LIQUIDS. INVERSE GAS CHROMATOGRAPHY IS A TECHNIQUE WHICH STUDIES THE INTERACTION OF GASES AND VAPOURS WITH A SURFACE - MEASUREMENTS ARE OFTEN MADE AT DIFFERENT TEMPERATURES SO THAT THESE EXPERIMENTS CAN BE CONSIDERED TO COME UNDER THE AUSPICES OF THERMAL ANALYSIS.
ATOMIC FORCE MICROSCOPY USES A FINE STYLUS TO MAP THE TOPOGRAPHY AND MECHANICAL PROPERTIES OF SURFACES TO HIGH SPATIAL RESOLUTION. BY CONTROLLING THE TEMPERATURE OF THE HEATED TIP AND/OR THE SAMPLE A FORM OF SPATIALLY RESOLVED THERMAL ANALYSIS CAN BE CARRIED OUT.
THERMAL ANALYSIS IS ALSO OFTEN USED AS A TERM FOR THE STUDY OF HEAT TRANSFER THROUGH STRUCTURES. MANY OF THE BASIC ENGINEERING DATA FOR MODELLING SUCH SYSTEMS COMES FROM MEASUREMENTS OF HEAT CAPACITY AND THERMAL CONDUCTIVITY.



for your projects on thermal analysis 
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Tuesday, 22 July 2014

multi body dynamics

Multi body system is the study of the dynamic behavior of interconnected rigid or flexible bodies, each of which may undergo large translational and rotational displacements.


The systematic treatment of the dynamic behavior of interconnected bodies has led to a large number of important multi body formalisms in the field of mechanics. The simplest bodies or elements of a multi body system were treated by Newton (free particle) and Euler (rigid body). Euler introduced reaction forces between bodies. Later, a series of formalisms were derived, only to mention Lagrange’s formalisms based on minimal coordinates and a second formulation that introduces constraints.


Basically, the motion of bodies is described by their kinematic behavior. The dynamic behavior results from the equilibrium of applied forces and the rate of change of momentum. Nowadays, the term multi body system is related to a large number of engineering fields of research, especially in robotics and vehicle dynamics. As an important feature, multi body system formalisms usually offer an algorithmic, computer-aided way to model, analyze, simulate and optimize the arbitrary motion of possibly thousands of interconnected bodies.

Applications
While single bodies or parts of a mechanical system are studied in detail with finite element methods, the behavior of the whole multi body system is usually studied with multi body system methods within the following areas:
·         Aerospace engineering (helicopter, landing gears, behavior of machines under different gravity conditions)
·         Biomechanics
·         Combustion engine, gears and transmissions, chain drivebelt drive
·         Dynamic simulation* Vehicle simulation (vehicle dynamicsrapid prototyping of vehicles, improvement of stability, comfort optimization, improvement of efficiency, ...)
·         Hoistconveyorpaper mill
·         Military applications
·         Particle simulation (granular media, sand, molecules)
·         Physics engine
·         Robotics







for your projects on multi body dynamics
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chennaicfdonline@gmail.com

CAD/CAE/CFD

COMPUTER-AIDED DESIGN (CAD) IS THE USE OF COMPUTER SYSTEMS TO ASSIST IN THE CREATION, MODIFICATION, ANALYSIS, OR OPTIMIZATION OF A DESIGN. CAD SOFTWARE IS USED TO INCREASE THE PRODUCTIVITY OF THE DESIGNER, IMPROVE THE QUALITY OF DESIGN, IMPROVE COMMUNICATIONS THROUGH DOCUMENTATION, AND TO CREATE A DATABASE FOR MANUFACTURING. CAD OUTPUT IS OFTEN IN THE FORM OF ELECTRONIC FILES FOR PRINT, MACHINING, OR OTHER MANUFACTURING OPERATIONS.
COMPUTER-AIDED DESIGN IS USED IN MANY FIELDS. ITS USE IN DESIGNING ELECTRONIC SYSTEMS IS KNOWN AS ELECTRONIC DESIGN AUTOMATION, OR EDA. IN MECHANICAL DESIGN IT IS KNOWN AS MECHANICAL DESIGN AUTOMATION (MDA) OR COMPUTER-AIDED DRAFTING (CAD), WHICH INCLUDES THE PROCESS OF CREATING A TECHNICAL DRAWING WITH THE USE OF COMPUTER SOFTWARE.
CAD SOFTWARE FOR MECHANICAL DESIGN USES EITHER VECTOR-BASED GRAPHICS TO DEPICT THE OBJECTS OF TRADITIONAL DRAFTING, OR MAY ALSO PRODUCE RASTER GRAPHICS SHOWING THE OVERALL APPEARANCE OF DESIGNED OBJECTS. HOWEVER, IT INVOLVES MORE THAN JUST SHAPES. AS IN THE MANUAL DRAFTING OF TECHNICAL AND ENGINEERING DRAWINGS, THE OUTPUT OF CAD MUST CONVEY INFORMATION, SUCH AS MATERIALS, PROCESSES, DIMENSIONS, AND TOLERANCES, ACCORDING TO APPLICATION-SPECIFIC CONVENTIONS.
CAD MAY BE USED TO DESIGN CURVES AND FIGURES IN TWO-DIMENSIONAL (2D) SPACE; OR CURVES, SURFACES, AND SOLIDS IN THREE-DIMENSIONAL (3D) SPACE.
CAD IS AN IMPORTANT INDUSTRIAL ART EXTENSIVELY USED IN MANY APPLICATIONS, INCLUDING AUTOMOTIVE, SHIPBUILDING, AND AEROSPACE INDUSTRIES, INDUSTRIAL AND ARCHITECTURAL DESIGN, PROSTHETICS, AND MANY MORE. CAD IS ALSO WIDELY USED TO PRODUCE COMPUTER ANIMATION FOR SPECIAL EFFECTS IN MOVIES, ADVERTISING AND TECHNICAL MANUALS, OFTEN CALLED DCC DIGITAL CONTENT CREATION. THE MODERN UBIQUITY AND POWER OF COMPUTERS MEANS THAT EVEN PERFUME BOTTLES AND SHAMPOO DISPENSERS ARE DESIGNED USING TECHNIQUES UNHEARD OF BY ENGINEERS OF THE 1960S. BECAUSE OF ITS ENORMOUS ECONOMIC IMPORTANCE, CAD HAS BEEN A MAJOR DRIVING FORCE FOR RESEARCH IN COMPUTATIONAL GEOMETRY,COMPUTER GRAPHICS (BOTH HARDWARE AND SOFTWARE), AND DISCRETE DIFFERENTIAL GEOMETRY.




COMPUTER-AIDED ENGINEERING (CAE) IS THE BROAD USAGE OF COMPUTER SOFTWARE TO AID IN ENGINEERING ANALYSIS TASKS. IT INCLUDESFINITE ELEMENT ANALYSIS (FEA), COMPUTATIONAL FLUID DYNAMICS (CFD), MULTIBODY DYNAMICS (MBD), AND OPTIMIZATION.








Software tools that have been developed to support these activities are considered CAE tools. CAE tools are being used, for example, to analyze the robustness and performance of components and assemblies. The term encompasses simulation, validation, and optimization of products and manufacturing tools. In the future, CAE systems will be major providers of information to help support design teams in decision making.
In regard to information networks, CAE systems are individually considered a single node on a total information network and each node may interact with other nodes on the network.
CAE systems can provide support to businesses. This is achieved by the use of reference architectures and their ability to place information views on the business process. Reference architecture is the basis from which information model, especially product and manufacturing models.
The term CAE has also been used by some in the past to describe the use of computer technology within engineering in a broader sense than just engineering analysis. It was in this context that the term was coined by Jason Lemon, founder of SDRC in the late 1970s. This definition is however better known today by the terms CAx and PLM.


for your final year project titles based on cad/cae/cfd

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