What is the purpose of a shear stress analysis in machine design?
A Optimize weight
B Prevent vibration
C Reduce speed
D Predict failure
Shear stress analysis predicts the failure of materials subjected to shear forces. It helps designers ensure that the material can withstand forces acting parallel to its surface, preventing structural damage or catastrophic failure.
Which is a common failure mode of machine components under dynamic loading?
A Yielding failure
B Fatigue failure
C Corrosion
D Torsional failure
Fatigue failure occurs when a component is subjected to repeated or cyclic loading. Over time, this causes the material to develop microscopic cracks that eventually lead to complete failure, even if the stress is below the material’s yield strength.
Which property is crucial for selecting materials for bearings in machine design?
A Hardness
B Thermal conductivity
C Wear resistance
D Color
Wear resistance is crucial for bearing materials, as bearings experience constant motion and friction. Materials with high wear resistance ensure that the bearings can last longer, reducing maintenance and enhancing the lifespan of machines.
What is the function of a rivet in machine design?
A To hold components
B To store energy
C To reduce vibration
D To increase strength
Rivets are mechanical fasteners used to permanently join two components together. They are commonly used in structural applications where welding or bolting is not feasible, providing strong, durable connections.
What does the factor of safety in machine design ensure?
A Reduced weight
B Increased energy efficiency
C Minimized material cost
D Avoids failure
The factor of safety is used to provide a safety margin against failure. It ensures that the machine component can handle unexpected loads or conditions beyond its expected operating range, preventing failure and ensuring reliable performance.
What is the role of a spring in machine design?
A To transfer motion
B To store energy
C To reduce friction
D To prevent overheating
Springs are used to store mechanical energy. They are designed to deform elastically when a force is applied, and then return to their original shape, thus storing and releasing energy as needed in mechanical systems like shock absorbers.
What does the term ‘torsion’ in machine design refer to?
A Rotational force
B Impact load
C Compressive force
D Stretching material
Torsion refers to the twisting of an object due to an applied torque or rotational force. In machine design, torsion is considered when designing shafts or other components that will undergo rotational forces to ensure they can handle the stresses without failure.
Which of the following is a primary concern when designing a welded joint?
A Weight
B Strength
C Cost
D Appearance
When designing welded joints, the primary concern is strength. The weld must be strong enough to bear the load without failure, and the material used should be compatible with the base materials to ensure a reliable connection.
What type of analysis is used to predict the failure of components due to excessive deformation?
A Fluid dynamics analysis
B Stress analysis
C Buckling analysis
D Thermal analysis
Buckling analysis predicts the failure of components under compressive forces. If a component is slender or not well-supported, buckling can occur, leading to deformation and failure. Engineers use this analysis to design stable and safe components.
Which machine design component is primarily responsible for transmitting torque between shafts?
A Rivet
B Gear
C Clutch
D Bolt
Gears are used to transmit torque between shafts in mechanical systems. They alter rotational speed, direction, and torque, making them essential for efficient power transmission and motion control in machines.
In which type of loading is a material subjected to both tensile and compressive forces?
A Bending
B Torsion
C Dynamic
D Shear
Bending loading involves a material being subjected to both tensile and compressive forces. As the material bends, one side experiences tension, while the opposite side experiences compression. Engineers must design materials to handle these forces without failure.
Which type of material is commonly used for shafts subject to torsion in machine design?
A Wood
B Plastic
C Steel
D Aluminum
Steel is commonly used for shafts subject to torsion due to its high tensile and shear strength. It can withstand twisting forces without breaking or deforming, making it an ideal material for many mechanical components like shafts.
What type of analysis is often used to simulate and optimize machine designs?
A Stress-strain analysis
B Finite element analysis
C Failure analysis
D Thermal analysis
Finite element analysis (FEA) is a numerical method used to simulate and optimize machine designs. It breaks down a structure into small, manageable elements to study stress, strain, and other physical phenomena, helping to improve design efficiency and safety.
What is the purpose of lubrication in machine design?
A To strengthen material
B To increase friction
C To reduce wear
D To cool components
Lubrication is used to reduce wear by minimizing direct contact between moving parts, thereby lowering friction. It also helps to dissipate heat and prolong the lifespan of machine components by reducing the chances of overheating and excessive wear.
Which of the following is a common method for joining machine parts in machine design?
A Soldering
B Painting
C Insulating
D Riveting
Riveting is a common method used to join machine parts, especially in applications where welding or bolting is not feasible. Rivets provide strong and permanent connections between components, often used in structural applications like bridges and aircraft.
