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 ).
Get link
Facebook
X
Pinterest
Email
Other Apps
Frames and Machines
Get link
Facebook
X
Pinterest
Email
Other Apps
-
Truss and it's Types:
Truss is a structure of connected elements forming triangular units, and a bridge whose load-bearing superstructure is composed of a truss.
There are three types of truss and they are:
1. Simple Truss:
A truss is a structure composed of slender members joined together at their end points.
2. Planar Truss:
Planar truss lies in single plane and typically used in parallel to form roofs and bridges.
3. Space Truss:
A space Truss consists of members joined together at their ends to form a stable three-dimensional structure.
Assumptions for Designing Truss:
To design the truss, we have two assumptions:
All loadings are applied at the joints.
The members are joined by smooth pins.
The Method of Joints:
In order to analyze or design a truss, it is necessary to determine the forces in each of its members. Method of joints consists of fool owing steps:
Truss is in equilibrium so does its joints.
Draw Free-body diagrams for each joint.
Apply the force equilibrium equations and obtain the required ones.
ΣFx = 0
ΣFy = 0
The Method of Sections:
By using the method of sections, you need to follow the instructions below:
Truss is in equilibrium so does the segments of truss.
Draw free Body diagram indicating all forces.
Cut the free Body diagram into its simple parts.
Apply the equilibrium equations to find the required forces and moments.
ΣFx = 0
ΣFy = 0
ΣMo = 0
Zero Force Members:
Zero-force members in a truss members which do not have any force in them. Zero-force members are used to increase the stability of the truss during construction and to provide added support of the loading is changed.
Frames:
Frames used to support loads which are often composed of pin-connected multi-force members that are subjected to more than two forces.
Machines:
Machines contain moving parts which are often composed of pin-connected multi-force members that are subjected to more than two forces.
Solid Mechanics OR Mechanics of Materials OR Strength of Materials: 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 tend...
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...
Gear Generation by Machining Tooth profile is provided by much simpler form cutting tool through hobbing, gear shaping. It involves the following methods: Gear Hobbing Gear Shaping 1. Gear Hobbing It is defined as, " a machining process in which gear teeth are progressively generated by a series of cuts with a helical cutting tool " . Most accurate machining process. Used for gears production because it has excellent surface finish. Continuous Indexing Process ↠ in which both cutting tool and workpiece rotate in constant relationship while hob is being fed into work. Feed Directions The direction of feed during hobbing operation depends upon the type of gear to be cut. Following are the types of feed directions: Axial Feeding ↠ cutting spur and helical gears (Hob axis is parallel to Blank axis). Radial Feeding ↠ for bevel gears (Hob axis is perpendicular to Blank axis). Tangential Feeding ↠ for worm, straight, spiral...
Comments
Post a Comment
HI, we wI'll contact you later