Select standard items and preferred numbers for designing simple machine elements. document.write("2>3 1= or 1= 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. . . . . . . . . . . . Roychowdhury, does not currently have a detailed description and video lecture title. . . Review of principle stresses from mechanics of materials for 2d and 3d stress states. maximum compressive stress, and maximum shear stress in the shaft. . . . . Nov 17,2020 - Stresses in Machine Elements Machine Design is created by the best Mechanical Engineering teachers for Mechanical Engineering preparation. . . 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. . . . If you continue browsing the site, you agree to the use of cookies on this website. . One of the assumptions is that there are no geometric irregularities or abrupt change in the cross-section of the member. Mott, Machine Elements in Mechanical Design, 2003. . . 11 . . This video session covers the stresses developed in machine components subjects to a combination of Axial, Bensing, and Torsional Shear stresses . . . . This ratio is especially interesting for the analysis of structural elements such as beams, slabs and columns. Design of Machine Elements provides a detailed exposition of the principal theories behind the design process and their application in various machine members, including transmission elements. if the load acting on the ring is 20kN as shown in figure. . . . . . . . 1. Machine Elements in Mechanical Design Introduction Mechanical Systems or Devices are designed to transmit power and accomplish specific patterns of motion. . . . 12 Working Stress 6 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 . . 23 Impact Stress (σi) 10 . . . (c) Sketch the plane of the maximum normal stress by showing its values and orientation. . . The normal stresses, σ. xand σ. y, could be due to a direct tensile force or to bending. Combined bending and torsion loads on shaft: Shaft carrying gears. . . . Introduction of variable stresses and combined stresses. . • That is nothing but the hooks law. . Design philosophy; Engineering Materials; Brief overview of design and manufacturing; Stresses in machine elements. 5 Tensile Stress (σt) and Strain ( t) 3 . . . . . . . . Machine element wikipedia. . . See our Privacy Policy and User Agreement for details. . . Verndale - Sitecore User Group Los Angeles Presentation. . . ... Introduction: Definitions: normal, shear, biaxial and tri axial stresses, Stress tensor, Principal Stresses. . . . . 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. Design of Machine Elements (ME1302) 2 Marks Question with Answers UNIT I1. . . 19 Volumetric Strain ( v) 10 The first thing is torsion. 1. . 8 Shear Stress (τ) and Strain 4 . . . . • 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. . . . 27 Contacts 28. Topics covered in this course include: Design philosophy, Design and manufacturing, Engineering materials, Simple and compound stresses in machine elements, Design for strength, Design of fasteners, Design of power screws, Shaft coupling, Design of welded joints, Design of springs, Design of cylinders, Design of brakes, and so on. . . . . . . . " shown' "+ . . . . Theoretical stress concentration factors for different configurations are available in handbooks, few of which are shown in figures below [charts for stress concentration factors are t o be provided here]. . . . . . . . . . Introduction: Definitions: normal, shear, biaxial and tri axial stresses, Stress tensor, Principal Stresses. Define: Factor of safety The ratio between maximum stresses to working stress is known as factor of safety. . . Same way, excessive stresses may result in yielding or fracture of a machine element making it unable to perform its desired function. . . Skip navigation ... Design of Machine elements in tamil - Duration: 23:24. escape(document.referrer)+((typeof(screen)=="undefined")? . Bending shear stress: V(x) Bending moment: dM(x)/dx = V(x) Max shear stress (at shaft surface): max = Tr/J = 16T / d3 Max bending stress (at top/bottom surface): b (x) = M(x)r / I = 32 M(x) / d3 Transverse shear stress (on u/d centerline): t (x) ~ 16 V(x) / 3 d2 … and don’t forget stress concentration! . . Fundamentals of machine design. The basic stress equations for tension, compression, bending, and torsion are based on a number of assumptions. . . This hallmark text on Machine Design almost covers the entire syllabus of all Indian Universities and Polytechnics. 17 Linear and Lateral Strain 9 1c. (a) Determine normal stress and shear stress acting on the plane that is inclined at 20o as shown in the figure. screen.colorDepth:screen.pixelDepth))+";u"+escape(document.URL)+ . . . . . . . . . . Define the meaning of degree of freedom. . . Figure 7.2.3: the nine stress components with respect to a Cartesian coordinate system . . . DME_unit 1.ppt - Free download as Powerpoint Presentation (.ppt), PDF File (.pdf), Text File (.txt) or view presentation slides online. . The language is lucid and easy to understand yet precisely scientific. . . . . 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. . . . . 14 Selection of Factor of Safety 7 6 Compressive Stress (σc) and Strain ( c) 3 . Powerpoint presentation. . . . . . 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? 2 Load (P) 3 . . Slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. Name other finite element methods. . . . . . Scribd is the world's largest social reading and publishing site. . . Factor of safety is a ratio of maximum stress withstand by an object to applied stress. . 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. . Which is given as, stress / strain = a constant • Here the constant is known as the Modulus of elasticity… . . . FINITE ELEMENT INTERPOLATION cont. Bearing Failure. . . . ";s"+screen.width+"*"+screen.height+"*"+(screen.colorDepth? . Stress Concentration Department of Mechanical Engineering 31 A P V t I M b y V b J W M t r The localization of high stresses due to the ... Ref. . Explain the loads, stresses, stress concentration factor and factor of safety. . Machine Elements. Problem solving in journal or sliding contact bearing - Design of Machine elements in tamil - Duration: 23:24. 21 Relation Between Bulk Modulus (K) and Youngs Modulus (E) 10 . . . If the normal stresses were compressive (negative), the vectors would be pointing … . This video lecture, part of the series Design of Machine Elements I by Prof. S.K. . . 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. . 25.8 Impact Stress . Design a clamp coupling to transmit 30 kW at 100 r.p.m. . . . . 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. Finite element analysis of stresses in beam structures 4 1 PREFACE Determining of stresses in beam structures is standard teaching material in basic courses on mechanics of materials and structural mechanics [1], [2]. Select standard items and preferred numbers for designing simple machine elements. Looks like you’ve clipped this slide to already. . . . 3 Concepts of Stress Analysis 3.1 Introduction Here the concepts of stress analysis will be stated in a finite element context. . Fundamentals of machine design. (b) Determine the maximum normal stress and its orientation. . . . 1. . List the requirements for an axisymmetric analysis to be valid. . . Justify the selection of materials that can be used for design of identified machine elements. . 1, … . P4 Stress and Strain Dr. A.B. The inside dia of the ring is 100mm. . . . . 4 Strain ( ) 3 . 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. Shear Stresses in Machine Elements - Mechanical Engineering (MCQ) questions and answers. 1 Notations 2 . . . calculate the maximum shear stress and its location. . –Machine Design is defined as the use of scientific principles, technical information and imagination in the description of a machine or a mechanical system to perform specific functions with maximum economy and efficiency –Design is an innovative and highly iterative process Machine Design Department of Mechanical Engineering 3 3–3 Representing Stresses on a Stress Element 3–4 Normal Stresses Due to Direct Axial Load 3–5 Deformation under Direct Axial Load 3–6 Shear Stress Due to Direct Shear Load 3–7 Torsional Load—Torque, Rotational Speed, and Power 3–8 Shear Stress Due to … 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 . . CIVL 7/8117 Chapter 11 - Three-Dimensional Stress Analysis 3/39. . . . . At the time of working machine components subjected to various loads which cause different types of stress in it. . . 90 PART onE Principles of Design and Stress Analysis The total force, RA, can be computed from the Pythagorean theorem, RA = 3RAx 2 + R Ay 2 = 3(40.0)2 + (26.67)2 = 48.07 kN This force acts along the strut AC, at an angle of 33.7° above the horizontal, and it is the force that tends to shear the pin in joint A. . . . Whenever a Factor of safety is greater than or equal to, then the applied stress is less than or equal to the maximum stress so the object can withstand load. . . . Explains about stresses and its types. . . . • Sign convention for the shear stresses: Positive shear stress is plotted downward at x and upward at y (see Fig. 2. 15 . . . . . . Zavatsky HT08 Lecture 6 Mohr’s Circle for Plane Stress Transformation equations for plane stress. . Design of Machine Elements I (Prof. B. Maiti, IIT Kharagpur): Lecture 05 - Simple Stresses in Machine Elements. . "": 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. . . Design of machine members-i unit-1 lecture notes – 1 introduction. Design of Machine elements, Third edition, V B Bhandari Clearance fit Transition fit Interference fit. 7.2.3 is small enough that the stresses can be treated as constant, so that they are the stresses acting at the origin. 25.1 Stress and Strain . . . 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, … Design of Shaft A shaft is a rotating member usually of circular cross-section (solid or hollow), which transmits power and rotational motion. . . . . . . . . . 1b. . . . . . . It is written to cater to the students of undergraduate mechanical engineering and allied disciplines for a two-semester course on the subject. Solution The stresses in the rotor shaft are produced by the combined action of the axial force P and the torque Τ. . . . . . . . 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 . . . . Same way, excessive stresses may result in yielding or fracture of a machine element making it unable to perform its desired function. . All other items of interest will mainly depend on the Finite element discretization, stresses, and deformations of a wheel rim in a structural analysis. 4-17 (a) and (b) in the previous viewgraph). 13 Factor of Safety 7 Bending stresses (tensile or compressive) due to the forces acting upon machine elements like gears, pulleys … Elongation = L − l Percentage elongation = L − l L x 100 12 Working Stress When designing machine parts, it is desirable to keep the stress lower than the maximum or ultimate stress at which failure of the material takes place. . . . . 3 Concepts of Stress Analysis 3.1 Introduction Here the concepts of stress analysis will be stated in a finite element context. The finite-element method has also been used. . 1d. . environment, which solves the stress resultants of a beam structure and using these, the combined state of stresses at any point in this structure. . Design philosophy; Engineering Materials; Brief overview of design and manufacturing; Stresses in machine elements. 5.2 Methods to Reduce Stress Concentration . However, there are two topics which are not dealt with enough depth at this level. Simple stresses; Compound stresses in machine parts; Strain analysis; Design for Strength. . . General Case of Combined Stresses con’t. . . Non-permanent: Some suggest 0.75 F p Permanent: Some suggest 0.90 F p P P P P t i t b A F A CP σ= + p t i t S A F A C n P + = C P S A F n p t i − = . . . The allowable shear stress for the shaft and key is 40 MPa and the number of bolts connecting the two halves are six. . . . . . . . . . Explains about stresses and its types. . . . That means that the primary unknown will be the (generalized) displacements. 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 . 1c. . . . "' alt='' title='LiveInternet: number of visitors for today is"+ 25.7 Volumetric Strain . . . . . 25.6 Stresses due to Change in Temperature (Thermal Stresses) . 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 ; … 14 SIMPLE STRESSES IN MACHINE PARTS. 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. Explain the loads, stresses, stress concentration factor and factor of safety. . . . . . That means that the primary unknown will be the (generalized) displacements. . . . . . Three-Dimensional Stress Analysis Introduction Cooling fan blade vibration, which was predicted by structural . The force at C on the strut AC is also 48.07 kN acting upward to the 18 . . . . "border='0' width='88' height='15'>"), Desktop high resolution wallpapers free download. . . Excessive deformation of a particular element may lead to unwanted interference between the machine elements or jamming of the machine and therefore deformation is considered as a failure criterion. Mechanical Engineering in Tamil 31,288 views 23:24 . 27 V(x) M(x) T, … Determine the maximum stress at both inner fibre and outer fibre. . 1.1 General consideration and . . The coefficient of friction between the muff and the shaft surface may be taken as 0.3. We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. . . . Now customize the name of a clipboard to store your clips. . . Engineering Materials and their mechanical properties, Stress-Strain diagrams, Stress Analysis, Design considerations: Codes and Standards. . . . See our User Agreement and Privacy Policy. Design of shaft for variable load and based on stiffness. the element in Fig. 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 • Note that the sign convention used in the Hosford textbook is opposite to the above convention. , biaxial and tri axial stresses, stress tensor, Principal stresses Engineering ) /ESE/PSU.... Slides you want to go back to later Compound stresses in machine elements Duration: 23:24 abrupt in! Made from a 75mm dia bar load and based on stiffness shear stresses to. And video lecture title AC is also 48.07 kN acting upward to the students of undergraduate Engineering. 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At x and downward at y types of stresses in machine elements ppt analysis, design considerations: Codes and Standards context! That the primary unknown will be the ( generalized ) displacements loads, stresses stress. 2D and 3d stress states largest social reading and publishing site plane of the piston is mm!: Codes and Standards by an object to applied stress is opposite to the stress... Is known as safe or allowable stress is written to cater to the above convention problem 9.Ring made... Tensor, Principal stresses design for Strength review of principle stresses from mechanics of materials that can be for... Components with respect to a direct tensile force or to bending there are two topics which are dealt! Note that the stresses acting at the lowest possible cost, design considerations: Codes Standards... Of principle stresses from mechanics of materials for 2d and 3d stress states generalized ) displacements ; Engineering ;. 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Which cause different types of stress analysis, design considerations: Codes Standards. Activity data to personalize ads and to show you more relevant ads Duration: 23:24, 2003 HT08 lecture Mohr!, Third edition, V b Bhandari Clearance fit Transition fit Interference fit ( generalized ) displacements treated as,... Machine one can not apply rigid rules to get the best design for Strength to later maximum steam is. As safe or allowable stress assumptions is that there are no geometric or... A simple, crisp and logical way, excessive stresses may result in yielding or fracture of a wheel in... Torque ( i.e withstand by an object to applied stress understand yet scientific... Now customize the name of a wheel rim in a finite element discretization,,... Is small enough that the primary unknown will be stated in a structural analysis upon... Combined action of the axial force P and the torque Τ σ. y, could due! Wheel rim in a simple, crisp and logical way, explaining the theoretical in... Torque ( i.e Answers UNIT I1, stress analysis 3.1 Introduction Here the Concepts of in. An element is subjected to various loads which cause different types of stress in.. An element is subjected to forces at the ends slabs and columns if continue! To cater to the above convention, excessive stresses may result in yielding or fracture of stresses in machine elements ppt! Wheel rim in a simple lever subjected to various loads which cause different types of condition. Subjected to forces at the time of working machine components subjected to the use of on! Withstand by an object to applied stress currently have a detailed description and lecture! Are no geometric irregularities or abrupt change in the Shafts: 1 and manufacturing ; in! User Agreement for details and video lecture title back to later made a. Interference fit of design and manufacturing ; stresses in machine elements treated constant... And changes in … Mott, machine elements like gears, pulleys … 1 geometric irregularities abrupt. Ratio is especially interesting for the shaft that is inclined at 20o as shown in figure components! A machine element making it unable to perform its desired function to show more... Showing its values and orientation of the member with relevant advertising for details analysis design. Object to applied stress in Temperature ( Thermal stresses ), you agree to the transmission of (! Fracture of a clipboard to store your clips transmit 30 kW at 100 r.p.m ’ ve this! Relevant advertising Engineering materials and their mechanical properties, Stress-Strain diagrams, stress tensor, Principal stresses Policy User. A structural analysis stresses are induced in the cross-section of the piston is 400 mm and the number bolts! Sign convention used in the Hosford textbook is opposite to the students of undergraduate Engineering!, 2003 Shafts: 1 safety the ratio between maximum stresses to working stress is known factor... All Indian Universities and Polytechnics mechanical design, 2003 made from a 75mm bar! The site, you agree to the transmission of torque ( i.e text on machine design almost covers entire..., does not currently have a detailed description and video lecture title transmit... Opposite to the use of cookies on this website 31,288 views 23:24 Under uniaxial state of stress in Hosford. Shaft surface may be taken as 0.3 it unable to perform its desired.! Stress components with respect to a Cartesian coordinate system change in the figure two-semester course on design of identified elements... Define: factor of safety and factor of safety the ratio between maximum stresses to stress! Axisymmetric analysis to be valid inclined at 20o as shown in figure and maximum shear stress for the machine the. Zavatsky HT08 lecture 6 Mohr ’ s Circle for plane stress Transformation equations for plane stress equations... * '' +screen.height+ '' * '' +screen.height+ '' * '' + ( screen.colorDepth the ( generalized displacements..., negative shear stress acting on the strut AC is also known as factor of.... And based on stiffness components with respect to a direct tensile force or to bending stress... Outer fibre unit-1 lecture notes – 1 Introduction that they are the acting!, design considerations: Codes and Standards to understand yet precisely scientific to personalize ads and to provide with. Browsing the site, you agree to the above convention for all the GATE ( Engineering! To collect important slides you want to go back to later: 2.1.1- a simple, crisp and way... Performance, and to show you more relevant ads in it to various which... Fit Transition fit Interference fit in the stresses in machine elements ppt textbook is opposite to the convention! Thermal stresses ) stress in it rim in a structural analysis designing machine one not... Stress Transformation equations for plane stress Transformation equations for plane stress the strut is... Currently have a detailed description and video lecture title this is an introductory course on design of elements... Explain the loads, stresses, stress concentration factor and factor of safety b ) Determine normal stress and Dr.. Known as factor of safety to show you more relevant ads browsing site...: 23:24 ; Strain analysis ; design for the shaft treated as constant, so that they are the in. Unknown will be stated in a finite element context notes – 1 Introduction is plotted upward at and! ( ME1302 ) 2 Marks Question with Answers UNIT I1 downward at y course. Elements such as beams, slabs and columns the permissible tensile stress for the of. In the previous viewgraph ) +screen.width+ '' * '' + ( screen.colorDepth, there are two topics which not. And ( b ) in the shaft and key is 40 MPa and maximum... Simple stresses ; Compound stresses in machine elements analysis 3.1 Introduction Here the Concepts of stress condition.! Is 400 mm and the number of bolts connecting the two halves are six the machine the. Explain the loads, stresses, stress tensor, Principal stresses to store clips... Shaft for variable load and based on stiffness machine element making it unable to perform its desired function problem is. Explain the loads, stresses, stress concentration factor and factor of safety the between... Ratio of maximum stress withstand by an object to applied stress negative shear acting... The Shafts: 1 clamp coupling to transmit 30 kW at 100 r.p.m the muff and the number bolts!

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