Machine Elements Design interview questions

1. A.diameter from combined bending and torsion with shock factors, using maximum shear stress theory and allowable shear of 0.3 Sy or 0.18 Sut, whichever is smaller
2. B.life that 90% of a group of identical bearings will exceed, (C/P)³ million revolutions for ball bearings and exponent 10/3 for roller bearings
3. C.constant radial load a bearing can carry for a rating life of one million revolutions, the C value in catalogues
4. D.T = K·d·F with nut factor K about 0.2 for dry steel, which is why torque control gives roughly ±25% preload scatter

Answer + AI explanation with Pro

1. A.Bearing L10 life
2. B.Fillet weld throat
3. C.Bolt preload
4. D.Spring surge

Answer + AI explanation with Pro

1. A.Bearing L10 life — resonance of a helical spring when operating frequency nears its own natural frequency, avoided by keeping natural frequency 15–20 times the operating frequency
2. B.Bearing L10 life — minimum weld cross-section equal to 0.707 times the leg size, the plane on which weld shear stress is calculated
3. C.Bearing L10 life — surface fatigue from repeated Hertzian contact stress, the governing failure mode for hardened gears sized by the contact stress equation
4. D.Bearing L10 life — life that 90% of a group of identical bearings will exceed, (C/P)³ million revolutions for ball bearings and exponent 10/3 for roller bearings

Answer + AI explanation with Pro

1. A.constant radial load a bearing can carry for a rating life of one million revolutions, the C value in catalogues
2. B.surface fatigue from repeated Hertzian contact stress, the governing failure mode for hardened gears sized by the contact stress equation
3. C.T = K·d·F with nut factor K about 0.2 for dry steel, which is why torque control gives roughly ±25% preload scatter
4. D.resonance of a helical spring when operating frequency nears its own natural frequency, avoided by keeping natural frequency 15–20 times the operating frequency

Answer + AI explanation with Pro

1. A.Gear tooth pitting
2. B.Basic dynamic load rating
3. C.Spring surge
4. D.Bearing L10 life

Answer + AI explanation with Pro

1. A.Basic dynamic load rating — Lewis-based tooth stress multiplied by overload, dynamic, size, load-distribution and rim-thickness factors before comparison with the allowable
2. B.Basic dynamic load rating — resonance of a helical spring when operating frequency nears its own natural frequency, avoided by keeping natural frequency 15–20 times the operating frequency
3. C.Basic dynamic load rating — constant radial load a bearing can carry for a rating life of one million revolutions, the C value in catalogues
4. D.Basic dynamic load rating — life that 90% of a group of identical bearings will exceed, (C/P)³ million revolutions for ball bearings and exponent 10/3 for roller bearings

Answer + AI explanation with Pro

1. A.minimum weld cross-section equal to 0.707 times the leg size, the plane on which weld shear stress is calculated
2. B.resonance of a helical spring when operating frequency nears its own natural frequency, avoided by keeping natural frequency 15–20 times the operating frequency
3. C.diameter from combined bending and torsion with shock factors, using maximum shear stress theory and allowable shear of 0.3 Sy or 0.18 Sut, whichever is smaller
4. D.life that 90% of a group of identical bearings will exceed, (C/P)³ million revolutions for ball bearings and exponent 10/3 for roller bearings

Answer + AI explanation with Pro

1. A.ASME shaft design
2. B.Fillet weld throat
3. C.Torque-tension relation
4. D.Spring surge

Answer + AI explanation with Pro

1. A.Fillet weld throat — T = K·d·F with nut factor K about 0.2 for dry steel, which is why torque control gives roughly ±25% preload scatter
2. B.Fillet weld throat — constant radial load a bearing can carry for a rating life of one million revolutions, the C value in catalogues
3. C.Fillet weld throat — initial tension of about 75% of proof load for reusable and 90% for permanent joints, so the external load only slightly raises bolt stress
4. D.Fillet weld throat — minimum weld cross-section equal to 0.707 times the leg size, the plane on which weld shear stress is calculated

Answer + AI explanation with Pro

1. A.constant radial load a bearing can carry for a rating life of one million revolutions, the C value in catalogues
2. B.Lewis-based tooth stress multiplied by overload, dynamic, size, load-distribution and rim-thickness factors before comparison with the allowable
3. C.T = K·d·F with nut factor K about 0.2 for dry steel, which is why torque control gives roughly ±25% preload scatter
4. D.surface fatigue from repeated Hertzian contact stress, the governing failure mode for hardened gears sized by the contact stress equation

Answer + AI explanation with Pro

1. A.Bearing L10 life
2. B.Fillet weld throat
3. C.Bolt preload
4. D.AGMA bending stress

Answer + AI explanation with Pro

1. A.AGMA bending stress — initial tension of about 75% of proof load for reusable and 90% for permanent joints, so the external load only slightly raises bolt stress
2. B.AGMA bending stress — diameter from combined bending and torsion with shock factors, using maximum shear stress theory and allowable shear of 0.3 Sy or 0.18 Sut, whichever is smaller
3. C.AGMA bending stress — constant radial load a bearing can carry for a rating life of one million revolutions, the C value in catalogues
4. D.AGMA bending stress — Lewis-based tooth stress multiplied by overload, dynamic, size, load-distribution and rim-thickness factors before comparison with the allowable

Answer + AI explanation with Pro

1. A.life that 90% of a group of identical bearings will exceed, (C/P)³ million revolutions for ball bearings and exponent 10/3 for roller bearings
2. B.surface fatigue from repeated Hertzian contact stress, the governing failure mode for hardened gears sized by the contact stress equation
3. C.constant radial load a bearing can carry for a rating life of one million revolutions, the C value in catalogues
4. D.diameter from combined bending and torsion with shock factors, using maximum shear stress theory and allowable shear of 0.3 Sy or 0.18 Sut, whichever is smaller

Answer + AI explanation with Pro

1. A.ASME shaft design
2. B.Spring surge
3. C.Gear tooth pitting
4. D.Fillet weld throat

Answer + AI explanation with Pro

1. A.ASME shaft design — Lewis-based tooth stress multiplied by overload, dynamic, size, load-distribution and rim-thickness factors before comparison with the allowable
2. B.ASME shaft design — T = K·d·F with nut factor K about 0.2 for dry steel, which is why torque control gives roughly ±25% preload scatter
3. C.ASME shaft design — initial tension of about 75% of proof load for reusable and 90% for permanent joints, so the external load only slightly raises bolt stress
4. D.ASME shaft design — diameter from combined bending and torsion with shock factors, using maximum shear stress theory and allowable shear of 0.3 Sy or 0.18 Sut, whichever is smaller

Answer + AI explanation with Pro

1. A.constant radial load a bearing can carry for a rating life of one million revolutions, the C value in catalogues
2. B.Lewis-based tooth stress multiplied by overload, dynamic, size, load-distribution and rim-thickness factors before comparison with the allowable
3. C.T = K·d·F with nut factor K about 0.2 for dry steel, which is why torque control gives roughly ±25% preload scatter
4. D.initial tension of about 75% of proof load for reusable and 90% for permanent joints, so the external load only slightly raises bolt stress

Answer + AI explanation with Pro

1. A.Spring surge
2. B.Torque-tension relation
3. C.AGMA bending stress
4. D.Bolt preload

Answer + AI explanation with Pro

1. A.Bolt preload — T = K·d·F with nut factor K about 0.2 for dry steel, which is why torque control gives roughly ±25% preload scatter
2. B.Bolt preload — Lewis-based tooth stress multiplied by overload, dynamic, size, load-distribution and rim-thickness factors before comparison with the allowable
3. C.Bolt preload — minimum weld cross-section equal to 0.707 times the leg size, the plane on which weld shear stress is calculated
4. D.Bolt preload — initial tension of about 75% of proof load for reusable and 90% for permanent joints, so the external load only slightly raises bolt stress

Answer + AI explanation with Pro

1. A.constant radial load a bearing can carry for a rating life of one million revolutions, the C value in catalogues
2. B.T = K·d·F with nut factor K about 0.2 for dry steel, which is why torque control gives roughly ±25% preload scatter
3. C.surface fatigue from repeated Hertzian contact stress, the governing failure mode for hardened gears sized by the contact stress equation
4. D.diameter from combined bending and torsion with shock factors, using maximum shear stress theory and allowable shear of 0.3 Sy or 0.18 Sut, whichever is smaller

Answer + AI explanation with Pro

1. A.Torque-tension relation
2. B.Bearing L10 life
3. C.Fillet weld throat
4. D.Gear tooth pitting

Answer + AI explanation with Pro

1. A.Torque-tension relation — diameter from combined bending and torsion with shock factors, using maximum shear stress theory and allowable shear of 0.3 Sy or 0.18 Sut, whichever is smaller
2. B.Torque-tension relation — life that 90% of a group of identical bearings will exceed, (C/P)³ million revolutions for ball bearings and exponent 10/3 for roller bearings
3. C.Torque-tension relation — T = K·d·F with nut factor K about 0.2 for dry steel, which is why torque control gives roughly ±25% preload scatter
4. D.Torque-tension relation — resonance of a helical spring when operating frequency nears its own natural frequency, avoided by keeping natural frequency 15–20 times the operating frequency

Answer + AI explanation with Pro

1. A.resonance of a helical spring when operating frequency nears its own natural frequency, avoided by keeping natural frequency 15–20 times the operating frequency
2. B.Lewis-based tooth stress multiplied by overload, dynamic, size, load-distribution and rim-thickness factors before comparison with the allowable
3. C.initial tension of about 75% of proof load for reusable and 90% for permanent joints, so the external load only slightly raises bolt stress
4. D.T = K·d·F with nut factor K about 0.2 for dry steel, which is why torque control gives roughly ±25% preload scatter

Answer + AI explanation with Pro

1. A.Gear tooth pitting
2. B.Bolt preload
3. C.ASME shaft design
4. D.Spring surge

Answer + AI explanation with Pro

1. A.Spring surge — constant radial load a bearing can carry for a rating life of one million revolutions, the C value in catalogues
2. B.Spring surge — surface fatigue from repeated Hertzian contact stress, the governing failure mode for hardened gears sized by the contact stress equation
3. C.Spring surge — resonance of a helical spring when operating frequency nears its own natural frequency, avoided by keeping natural frequency 15–20 times the operating frequency
4. D.Spring surge — Lewis-based tooth stress multiplied by overload, dynamic, size, load-distribution and rim-thickness factors before comparison with the allowable

Answer + AI explanation with Pro

1. A.minimum weld cross-section equal to 0.707 times the leg size, the plane on which weld shear stress is calculated
2. B.diameter from combined bending and torsion with shock factors, using maximum shear stress theory and allowable shear of 0.3 Sy or 0.18 Sut, whichever is smaller
3. C.initial tension of about 75% of proof load for reusable and 90% for permanent joints, so the external load only slightly raises bolt stress
4. D.surface fatigue from repeated Hertzian contact stress, the governing failure mode for hardened gears sized by the contact stress equation

Answer + AI explanation with Pro

1. A.AGMA bending stress
2. B.Gear tooth pitting
3. C.Torque-tension relation
4. D.Bearing L10 life

Answer + AI explanation with Pro

1. A.Gear tooth pitting — initial tension of about 75% of proof load for reusable and 90% for permanent joints, so the external load only slightly raises bolt stress
2. B.Gear tooth pitting — surface fatigue from repeated Hertzian contact stress, the governing failure mode for hardened gears sized by the contact stress equation
3. C.Gear tooth pitting — T = K·d·F with nut factor K about 0.2 for dry steel, which is why torque control gives roughly ±25% preload scatter
4. D.Gear tooth pitting — diameter from combined bending and torsion with shock factors, using maximum shear stress theory and allowable shear of 0.3 Sy or 0.18 Sut, whichever is smaller

Answer + AI explanation with Pro