Description : Notch sensitivity (q) is given by the equation _______ where K f = fatigue stress concentration factor and K t = theoretical stress concentration factor a. ( K f + 1 ) / ( K t – 1 ) b. ( K f – 1 ) / ( K t – 1 ) c. ( K f + 1 ) / ( K t + 1 ) d. ( K f - 1 ) / ( K t + 1 )
Last Answer : b. ( K f – 1 ) / ( K t – 1 )
Description : The notch sensitivity q is expressed in terms of fatigue stress concentration factor Kf and theoretical stress concentration factor Kt as (A) (Kf + 1)/ (Kt + 1) (B) (Kf - 1)/ (Kt - 1) (C) (Kt + 1)/ (Kf + 1) (D) (Kt - 1)/ (Kf - 1)
Last Answer : (B) (Kf - 1)/ (Kt - 1)
Description : If a flat plate with a circular hole is subjected to tensile force, then its theoretical stress concentration factor is? a) 2 b) 3 c) 4 d) 1
Last Answer : b) 3
Description : Explain Notch Sensitivity. State The Relation Between Stress Concentration Factor And Notch Sensitivity?
Last Answer : Notch sensitivity (q) is the degree to which the theoretical effect of stress concentration is actually reached. The relation is, Kf = 1 + q (Kt-1)
Description : The relationship between the alternating stress and mean stress is given by the following equation: σ a =σ e [1-(σ m /σ u )x], where σ e is the fatigue limit for completely reversed loading. The value of x for Gerber line is equal to _________ a) 1 b) 2 c) 0.5 d) -1
Last Answer : b) 2
Description : Factor of safety for fatigue loading is the ratio of (a) elastic limit to the working stress (b) Young's modulus to the ultimate tensile strength (c) endurance limit to the working stress (d) elastic limit to the yield point
Last Answer : (c) endurance limit to the working stress
Description : Wahl factor to account for direct shear stress and stress concentration due to curvature for helical springs is given by, (A) (4C - 1/4C - 4) + 0.615/C (B) (4C - 1/4C + 4) + 0.615/C (C) (4C + 1/4C - 4) + 0.615/C (D) (4C + 1/4C + 4) + 0.615/C
Last Answer : (A) (4C - 1/4C - 4) + 0.615/C
Description : For a helical torsion sprig, the stress concentration factor at outer fibre is? Give spring index=5. a) 0.78 b) 0.87 c) 1.87 d) 0.69
Last Answer : b) 0.87
Description : What will happen if stresses induced due to surge in the spring exceeds the endurance limit stress of the spring. a) Fatigue Failure b) Fracture c) None of the listed d) Nipping
Last Answer : a) Fatigue Failure
Description : The endurance or fatigue limit is defined as the maximum value of the stress which a polished standard specimen can withstand without failure, for infinite number of cycles, when subjected to (a) static load (b) dynamic load (c) static as well as dynamic load (d) completely reversed load
Last Answer : (d) completely reversed load
Description : In S-N diagram, the graph plotted between fatigue strength and number of stress cycles becomes horizontal for which type of materials? a. Ferrous materials b. Non-ferrous materials c. Both a. and b. d. None of the above
Last Answer : a. Ferrous materials
Description : Deformation that occurs due to stress over a period of time is known as ____________ a) Wear resistance b) Fatigue c) Creep d) Fracture
Last Answer : c) Creep
Description : For a helical torsion sprig, the stress concentration factor at inner fibre is? Give spring index=5. a) 1.005 b) 1.175 c) 1.223 d) 1.545
Last Answer : b) 1.175
Description : In which of the following case stress concentration factor is ignored? a) Ductile material under static load b) Ductile material under fluctuating load c) Brittle material under static load
Last Answer : a) Ductile material under static load
Description : For an elliptical hole on a flat plate, if width of the hole in direction of the load decrease, Stress Concentration Factor will______ a) Increase b) Decrease c) Remains constant d) Can’t be determined. Varies from material to material
Last Answer : a) Increase
Description : Stress Concentration Factor is the ratio of nominal stress obtained by elementary equations for minimum cross- section and highest value of actual stress near discontinuity. a) True b) False
Last Answer : b) False
Description : Co-efficient of discharge (Cd ) is defined as actual discharge/theoretical discharge and is equal to Cc . Cv ; where Cc = Co-efficient of contraction and Cv = co-efficient of velocity. Cd of an orifice is usually about (A) 0.42 (B) 0.62 (C) 0.82 (D) 0.98
Last Answer : (B) 0.62
Description : Wahl suggested the correction in the stress factor to account for a. the additional transverse shear stress b. stress concentration c. fatigue stress d. axial stress
Last Answer : b. stress concentration
Description : If 8 bolts are emplaced in a clamp coupling with shaft diameter 80mm d, calculate the diameter of each bolt if coefficient of friction is 0.3 and torque transmitted is 4000N-m. Permissible tensile stress is 80N/mm2. a) 27mm b) 25mm c) 23mm d) 21mm
Last Answer : a) 27mm
Description : Calculate the skin depth of a conductor, having a conductivity of 200 units. The wave frequency is 10 GHz in air. a) 355.8 b) 3.558 c) 35.58 d) 0.3558
Last Answer : a) 355.8
Description : Which of the following formulae is used to calculate tangential stress, when a member is subjected to stress in mutually perpendicular axis and accompanied by a shear stress? a. [(σ x - σ y )/2 ]sin θ - τ cos 2θ b. [(σ x - ... τ cos 2θ c. [(σ x - σ y )/2 ]sin θ - τ 2 cos θ d. None of the above
Last Answer : c. [(σ x – σ y )/2 ]sin θ – τ 2 cos θ
Description : When a material is subjected to fatigue loading, the ratio of the endurance limit to the ultimate tensile strength is (a) 0.20 (b) 0.35 (c) 0.50 (d) 0.65
Last Answer : (c) 0.50
Description : Keyed joints never lead to stress concentration on shafts. a) True b) False
Description : The keyway, (A) Reduces strength of shaft (B) Reduces rigidity of shaft (C) Increases stress concentration (D) All of above
Last Answer : (D) All of above
Description : Stress concentration is caused due to A. Variation in properties of material from point to point in a member B. Pitting at points or areas at which loads on a member are applied C. Abrupt change of section D. All of the above
Last Answer : D. All of the above
Description : Which of the following reduces the stress concentration? a) Use of multiple notches b) Drilling additional holes c) Removal of undesired material d) Each of the mentioned
Last Answer : d) Each of the mentioned
Description : Use of multiple notches in a V shaped flat plate will a) Reduce the stress concentration b) Increase the stress concentration c) No effect d) Cannot be determined
Last Answer : a) Reduce the stress concentration
Description : Is it logical to use fluid analogy to understand the phenomenon of stress concentration? a) True b) False
Last Answer : a) True
Description : Stress concentration is defined as the localization of high stresses due to irregularities present in the component and no changes of the cross section. a) True b) False
Description : What Are The Factors That Affect Notch Sensitivity?
Last Answer : The factors effecting notch sensitivity are: 1. Material 2. Notch radius 3. Size of component 4. Type of loading 5. Grain Structure
Description : The theoretical stress-strain curve of the concrete in the Limit State design of structures is correspondingly reduced by the factor [ A ] 0.35 [ B ] 0.5 [ C ] 0.67 [ D ] 0.75
Last Answer : [ C ] 0.67
Description : _____ is a surface fatigue failure which occurs when the load on the bearing part exceeds the surface endurance strength of the material. (a) Scoring (b) Pitting (c) Corrosion
Last Answer : (b) Pitting
Description : Scoring is a ________ phenomenon. (a) stick-slip (b) fracture (c) fatigue (d) in-out
Last Answer : (a) stick-slip
Description : Extreme Pressure (EP) additives cause ______ wear in the bearing parts. (a) abrasive (b) corrosive (c) pitting (d) fatigue
Last Answer : (b) corrosive
Description : Scoring is a ________ phenomenon. a) Stick-slip b) Fracture c) Fatigue d) In-out
Last Answer : a) Stick-slip
Description : Propagation of fatigue failure is always due to compressive stresses. a) Due to bending b) Due to tensile c) Due to fatigue d) None of the listed
Last Answer : b) Due to tensile
Description : The connecting rod bolts are tightened up with the initial tension greater than external load so that (A) Failure of bolt will be static (B) The resultant load on bolt will not be affected by ... ) The bolt will not fail by fatigue although the external load is fluctuating (D) All the three
Last Answer : (D) All the three
Description : The yield point in static loading is ............... as compared to fatigue loading. (a) higher (b) lower (c) same
Last Answer : (a) higher
Description : The resistance to fatigue of a material is measured by (a) elastic limit (b) Young's modulus (c) ultimate tensile strength (d) endurance limit
Last Answer : (d) endurance limit
Description : Failure of a material is called fatigue when it fails (a) at the elastic limit (b) below the elastic limit (c) at the yield point (d) below the yield point
Last Answer : (d) below the yield point
Description : Does ASME Standard take into consideration shock and fatigue factors? a) Yes b) No
Last Answer : a) Yes
Description : There is sufficient plastic deformation prior to fatigue failure, which gives a warning well in advance. a) True b) False
Description : Fatigue failure is time dependent failure. a) True b) False
Description : The phenomenon of decreased resistance of the materials to fluctuating stresses is the main characteristic of _____ failure. a) Fracture b) Fatigue c) Yielding d) None of the mentioned
Last Answer : b) Fatigue
Description : The ability of materials to develop a characteristic behavior under repeated loading known as ___________ a) Toughness b) Resilience c) Hardness d) Fatigue
Last Answer : d) Fatigue
Description : Calculate natural frequency of damped vibration, if damping factor is 0.52 and natural frequency of the system is 30 rad/sec which consists of machine supported on springs and dashpots. A 25.62 rad/sec B 20.78 rad/sec C 14.4 rad/sec D 15.33 rad/sec
Last Answer : A 25.62 rad/sec
Description : Calculate natural frequency of damped vibration, if damping factor is 0.52 and natural frequency of the system is 30 rad/sec which consists of machine supported on springs and dashpots. A 21 rad/sec B 25.62 rad/sec C 20.22 Hz D 3.15 Hz
Last Answer : B 25.62 rad/sec