. . . . . Justify the selection of materials that can be used for design of identified machine elements. . . Stresses in Shafts The following stresses are induced in the shafts : 1. . . . 1 Notations 2 26 Slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. All other items of interest will mainly depend on the . . "target=_blank>2>3 1= or 1= Engineering Materials and their mechanical properties, Stress-Strain diagrams, Stress Analysis, Design considerations: Codes and Standards. . An element is subjected to the plane stresses shown in the figure. . Powerpoint presentation. The diameter of the piston is 400 mm and the maximum steam pressure is 0.9 N/mm2. . . . . All other items of interest will mainly depend on the Course is intended for Undergraduate Mechanical Engineering students involving detailed theory and related problems in Couplings, Clutches, Brakes, Belt, rope and chain drives, Gasket and sealing, Gears - types, nomenclature, related calculations and 2. . Determine the state of stress and I 1, I 2, and I 3 for an x', y', z' coordinate system defined by rotating x, y through an angle of q = 45° counterclockwise about the z axis . Select standard items and preferred numbers for designing simple machine elements. ... Introduction: Definitions: normal, shear, biaxial and tri axial stresses, Stress tensor, Principal Stresses. . . 3 Concepts of Stress Analysis 3.1 Introduction Here the concepts of stress analysis will be stated in a finite element context. 24 Resilience (U) 11 Machine element wikipedia. V(x) M(x) T, … . . 18 Poisson’s Ratio (µ) 9 . . . . . . screen.colorDepth:screen.pixelDepth))+";u"+escape(document.URL)+ . Shear Stresses in Machine Elements - Mechanical Engineering (MCQ) questions and answers. Name other finite element methods. . . . . . . 14 Selection of Factor of Safety 7 The stress tensor at a point in a machine element with respect to a Cartesian coordinate system is given by the following array: Equation f . . Consider a simple lever as shown in figure-2.1.1: 2.1.1- A simple lever subjected to forces at the ends. ";h"+escape(document.title.substring(0,150))+";"+Math.random()+ Slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. . . . Theories of failure help us to determine the safe dimensions of the machine components when they are subjected to bi-axial or tri-axial state of stresses. . . Design of Machine Elements by VB Bhandari . . Procedure to find the factor of safety and the safe diameter of the shafts using theories of failure . List the nodal degrees of freedom and the associated force actions for common beam, 2D solid, 2D axisymmetric, 3D solid and shell elements, for the Displacement FEM. . (b) Determine the maximum normal stress and its orientation. 14 . . Design of Shaft A shaft is a rotating member usually of circular cross-section (solid or hollow), which transmits power and rotational motion. . Massachusetts Institute of Technology 2.017 Images by Silberwolf, Red Rooster, ruizo, and Aspectomat at Wikimedia Commons, and i am indisposed and David on LRM on Flickr. . . . . . Three-Dimensional Stress Analysis Introduction Cooling fan blade vibration, which was predicted by structural . . 25.9 Resilience . . Stresses on an inclined element. . . . Mechanical Engineering in Tamil 31,288 views 23:24 . . . That means that the primary unknown will be the (generalized) displacements. . . . . 1b. . calculate the maximum shear stress and its location. 27 Contacts 28. • PROPORTIONAL LIMIT : It is the maximum stress at which the stress is proportional to strain and above this limit the plastic deformation of a material occurs. . The permissible tensile stress for the bolts is 70 MPa. 7.2.3 is small enough that the stresses can be treated as constant, so that they are the stresses acting at the origin. This stress is known as the working stress or design stress. Each chapter is written in a simple, crisp and logical way, explaining the theoretical considerations in design of machine elements. At the time of working machine components subjected to various loads which cause different types of stress in it. . Select standard items and preferred numbers for designing simple machine elements. Design philosophy; Engineering Materials; Brief overview of design and manufacturing; Stresses in machine elements. . . . . . . 25.1 Stress and Strain . . 3 Stress (σ) 3 . Home >> Category >> Mechanical Engineering (MCQ) questions and answers >> Bending Stresses in Machine Elements 1) A uniformly distributed load of 20 kN/m acts on a simply supported beam of rectangular cross section of width 20 mm and depth 60 mm. . . . . . . . . . . . . . . . Skip navigation ... Design of Machine elements in tamil - Duration: 23:24. . . (c) Sketch the plane of the maximum normal stress by showing its values and orientation. Machine element refers to an elementary component of a machine.These elements consist of three basic types: structural components such as frame members, bearings, axles, splines, fasteners, seals, and lubricants,; mechanisms that control movement in various ways such as gear trains, belt or chain drives, linkages, cam and follower systems, including brakes and clutches, and . . If J is polar moment of inertia and G is Modulus of Rigidity of coil, angular deflection of the wire due to twisting is given by, References. 16 Stresses due to Change in Temperature (Thermal Stresses) (σth) 9 of machine elements and design processes. . . . . Introduction: Definitions: normal, shear, biaxial and tri axial stresses, Stress tensor, Principal Stresses. . . . . . . . . . . . Which is given as, stress / strain = a constant • Here the constant is known as the Modulus of elasticity… 25.5 Stresses in Composite Bars . Must watch for all the GATE (Mechanical Engineering)/ESE/PSU Exams. The program thus consists of two main parts. . . Bearing Failure. . . . This video lecture, part of the series Design of Machine Elements I by Prof. S.K. . . . . . . . . . General Case of Combined Stresses con’t. . . . But when the ratio is equal to. 3-1 Equilibrium and Free-Body Diagrams 3-2 Shear Force and Bending Moments in Beams 3-3 Singularity Functions 3-4 Stress 3-5 Cartesian Stress Components 3-6 Mohr’s Circle for Plane Stress 3-7 General Three-Dimensional Stress 3-8 Elastic Strain 3-9 Uniformly Distributed Stresses 3-10 Normal Stresses for Beams in Bending 3-11 Shear Stresses for Beams in Bending 3-12 Torsion . Home >> Category >> Mechanical Engineering (MCQ) questions and answers >> Shear Stresses in Machine Elements; 1) What is the shear stress acting along the neutral axis, over a … . . . . 9 stresses: beams in bending. . . . . . Nov 17,2020 - Stresses in Machine Elements Machine Design is created by the best Mechanical Engineering teachers for Mechanical Engineering preparation. 19 Volumetric Strain ( v) 10 . . . . 21 . . . . Bending stresses (tensile or compressive) due to the forces acting upon machine elements like gears, pulleys … . Now customize the name of a clipboard to store your clips. . . Loads on shaft due to pulleys Torque and Bending moment diagrams for the pulley system Power, toque & speed For linear motion: Power = F.v (force x velocity) For rotational motion Power P = Torque x angular velocity = T (in-lb).w (rad/sec) in-lb/sec = T.(2 p n/60) in-lb/sec[n=rpm] = T.(2 p n/(60*12*550)) HP[HP=550 ft-lb/sec] = T.n/63,025 HP or, … . When designing machine one cannot apply rigid rules to get the best design for the machine at the lowest possible cost. . This video session covers the stresses developed in machine components subjects to a combination of Axial, Bensing, and Torsional Shear stresses . 9 Shear Modulus or Modulus of Rigidity (G) 5 . . Shear stresses due to the transmission of torque (i.e. . . . Figure 7.2.3: the nine stress components with respect to a Cartesian coordinate system . Design of Machine Elements I (Prof. B. Maiti, IIT Kharagpur): Lecture 05 - Simple Stresses in Machine Elements. . . . . . . Machine Elements. . . . It is written to cater to the students of undergraduate mechanical engineering and allied disciplines for a two-semester course on the subject. . . Factor of safety is a ratio of maximum stress withstand by an object to applied stress. . 2.1 Simple stresses Chapter 2 Stresses in machine elements Stresses are developed in machine elements due to applied load and machine design involves ensuring that the elements can sustain the induced stresses without yielding. – A free PowerPoint PPT presentation (displayed as a Flash slide show) on PowerShow.com - id: 43e60c-NTZmM . . . . . . Solution The stresses in the rotor shaft are produced by the combined action of the axial force P and the torque Τ. . SIMPLE STRESSES IN MACHINE PARTS. Same way, excessive stresses may result in yielding or fracture of a machine element making it unable to perform its desired function. . . Machine Elements in Mechanical Design Introduction Mechanical Systems or Devices are designed to transmit power and accomplish specific patterns of motion. . "border='0' width='88' height='15'>"), Desktop high resolution wallpapers free download. . . Verndale - Sitecore User Group Los Angeles Presentation. 25.6 Stresses due to Change in Temperature (Thermal Stresses) . On the contrary, negative shear stress is plotted upward at x and downward at y. It is also known as safe or allowable stress. FINITE ELEMENT INTERPOLATION cont. . . . . . . . . . . Another important element that we can calculate in the context of the basic stress analysis is the “Poisson’s ration” (μ) or the ratio of the lateral strain to the longitudinal strain. Scribd is the world's largest social reading and publishing site. . Explains about stresses and its types. . . 25.4 Stress-strain Diagram . . . of machine elements and design processes. Mechanical - Design of Machine Elements - Steady Stresses and Variable Stresses In Machine Members The piston rod of a steam engine is 50 mm in diameter and 600 mm long. . . That means that the primary unknown will be the (generalized) displacements. . Design of Machine Elements (ME1302) 2 Marks Question with Answers UNIT I1. . . 4-17 (a) and (b) in the previous viewgraph). . . 27 . . . . 25 Define: Factor of safety The ratio between maximum stresses to working stress is known as factor of safety. . The stress tensor at a point in a machine element with respect to a Cartesian coordinate system is given by the following array: Determine the state of stress and I1, I2, and I3 for an x' - y' - z' coordinate system defind by rotating x, y through an angle of 45 degree counterclockwise about the z axis. . . . . The permissible bearing pressure ([P bearing]) depends upon relative velocity, frequency of relative motion and the lubrication condition between the pin and the bush.The usual range of allowable bearing pressure for brass/bronze bush and steel pin is 10-25 N/mm 2.Lower values are used for high relative velocity, frequent motion and intermittent lubrication conditions. 4 Strain ( ) 3 . . 1. • Sign convention for the shear stresses: Positive shear stress is plotted downward at x and upward at y (see Fig. . . Maximum principal stress theory (Rankine’s theory) Department of Mechanical Engineering 31 The failure of mechanical component subjected to bi-axial or tri-axial stresses occurs when the maximum principal stress reaches the yield or ultimate strength of the material. Contents Under uniaxial state of stress condition i.e. 13 Factor of Safety 7 You can change your ad preferences anytime. . . CIVL 7/8117 Chapter 11 - Three-Dimensional Stress Analysis 3/39. . . 11 Stress-strain Diagram 6 . . . . "' alt='' title='LiveInternet: number of visitors for today is"+ The machine parts are subjected to various forces which may be due to either one or more of the following: Energy transmitted; Weight of Machine; Frictional resistance; Inertia of reciprocating parts; Change of temperature ; … Finite element discretization, stresses, and deformations of a wheel rim in a structural analysis. 5 Tensile Stress (σt) and Strain ( t) 3 Proof load and stress S p = proof stress = Limiting value of σ b (~ 0.85 σ y) Load factor (like a factor of safety) n > 1 ensures σ b < S p How high should the pre-load be? . . . . . . . The finite-element method has also been used. . Additionally, if we have elements that are subjected to both tension and compression at the same time, we use the bending stress formula which is “σb = 3 FL/2wt 2 ” where F is the force, L is the length of the structural element, w is the width, and t is its thickness. . . . . DME_unit 1.ppt - Free download as Powerpoint Presentation (.ppt), PDF File (.pdf), Text File (.txt) or view presentation slides online. . . . 16 . . . . of frame is grey cast iron whose ultimate tensile stress is 200 MPA and FOS =3. . Determine the maximum stress at both inner fibre and outer fibre. . . . . . The coefficient of friction between the muff and the shaft surface may be taken as 0.3. . . if the load acting on the ring is 20kN as shown in figure. Given : In this . • That is nothing but the hooks law. . But these irregularities and changes in … . Same way, excessive stresses may result in yielding or fracture of a machine element making it unable to perform its desired function. . . . . . . . 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