View Factor Orientation (or View factor or shape factor) plays an important role in radiation heat transfer. View factor is defined as, "fraction of radiation leaving surface 'i' and strike 'j' ". Summation Rule (View Factor) If there is are similar surfaces 'i' and 'j' , then: Blackbody Radiation Exchange Radiation Exchange between Opaque, Diffuse, Gray surfaces in an Enclosure 1. Opaque 2. Surfaces 3. Two surface enclosure Radiation Shield It is used to protect surfaces from radiation act like a reflective surface. References: Material from Class Lectures + Book named Fundamentals of Heat and Mass Transfer by Theodore L. Bergman + My knowledge. Photoshoped pics are developed. Some pics and GIF from Google. Videos from YouTube ( Engineering Sights ).
It is the study of mechanics of body i.e. forces and their effects on deformable solids under different loading conditions.
Deformable Body Mechanics:
It is the study of non-rigid solid structures which deform under load.
Deformation/Distortion ⇾ change of shape and size OR have some relative displacement or rotation of particles. It happens when we apply combined load.
Rigid Body Motion ⇾ Translation or rotation of particles but having constant distance between particles.
Since deformation occur at particular load. Below this load, every body is considered as rigid body.
Types of Load:
Point Load ⇾ Load apply on a single point i.e. concentrated load.
Uniformly Distributed Load (UDL) ⇾ Load remains uniform throughout an area of element like beam.
Varying Distributed Load (VDL) ⇾ Load varies with length with constant rate.
Moment ⇾ It measures the tendency of a body to rotate.
Distribution Of Forces:
Normal Force (N) ⇾ Force applied perpendicular to the area and is developed when external loads tend to push or pull the body.
Shear Force (V) ⇾ Force applied parallel to the area and is developed when external loads tend to slide.
Torsional Moment OR Torque (T) ⇾ External Force tends to twist a body.
Bending Moment (M) ⇾ External loads that tend to bend due to transverse loading.
Important Terms:
Transverse Loading ⇾ Load applied perpendicular to the axis of body.
Supports ⇾ Elements used to restrict motion of member.
Reactions⇾ These are forces produced due to those restrictions.
Degree of Freedom (DOF) ⇾ Number of independent coordinates in which an object can move.
Equilibrium of Forces ⇾ It prevents body from translating and having accelerated motion.
Equilibrium of Moment ⇾ It prevents body from rotating.
Procedure of Analysis:
Resultant internal force are required and can be found by the Method of Sections (require determinations of support reactions and resultant internal loads using equilibrium equations).
Steps are as follows:
Draw free-body diagrams using all external distributed loadings, couple moments, torques, forces at exact locations.
Determination of support reactions.
Determination of resultant internal force and moments using equilibrium equations.
References:
Material from Class Lectures + Book named Engineering Mechanics of Materials by R.C. Hibbeler (10th Edition) + my knowledge.
TAPING CORRECTIONS There are two types of corrections depending upon the type of errors in tape due to the different conditions. 1. Systematic Errors : Slope Erroneous tape length Temperature Tension Sag 2. Random Errors : Slope Alignment Marking & Plumbing Temperature Tension & Sag 1. Temperature Correction It is necessary to apply this correction, since the length of a tape is increased as its temperature is raised, and consequently, the measured distance is too small. It is given by the formula, C t = 𝛼 (T m – T o )L Where, C t = the correction for temperature, in m. 𝛼 = the coefficient of thermal expansion. T m = the mean temperature during measurement. T o = the tempe...
Gear Forming by Machining Formation of gear through machining consists of following methods: Form Milling by Disc Cutter Form Milling by End Mill Cutter Shaper, Planner and Slotter Broaching 1. Form Milling by Disc Cutter It is defined as, " Tooth is cut one by one by plunging the rotating cutter into the blank " . Each gear needs a separate cutter. 8 - 10 standard cutters are available for producing 12 - 120 teeth gears. Used for big spur gears of large pitch. 2. Form Milling by End Mill Cutter It includes the cutting of tooth at a time and then indexed for the next tooth space for cutting. For a small volume production of low precision gears. Set of 10 cutters ↠ 12 - 120 teeth gears . Used for teeth of large gears/module. To reduce cost, same cutter is often used for multiple sized gears resulting in profile errors . Characteristics: Use of Hardened stainless steels (HSS) form milling cutters. Use of Ordinary milling machines. Low production rate (need of indexing...
Diffusion It is defined as, " The transportation of one atom from one state into other state " . Used for hardening of surfaces like die parts, gear, bolt, machine element. Hardening can be done using Temperature-Heat treatment ( diffusion couple ). There are two types of diffusion: Inter-diffusion ↔ in which atoms tend to migrate from region of high concentration to low concentration . Self-diffusion ↔ in which atoms migrate within a solid. Diffusion Mechanism There can be two conditions of moving atoms Empty spaces between adjacent sites. Atoms have sufficient energy to break bond with neighbors atoms which cause lattice distortion during displacement. If we rise temperature, small fractions of atoms is capable of diffusive motion (which cause lattice distortion). Types of Diffusion 1. Vacancy Diffusion It is defined as, " interchange of an atom from a normal lattice position to the adjacent vacant lattice site " . Extent of vacancy diffusion is a function...
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