In concentric springs, vibrations called surge are amplified.
Explantion: Surge are eliminated.
Can concentric springs be used to obtain a force which is not proportional to its deflection?
Explanation: Two sprigs having different free length can be meshed to obtain such a result.
The load shared by each spring is inversely proportional to the cross section of wire.
Explanation: It is directly proportional to the cross section of wire.
A concentric spring consists of 2 sprigs of diameter 10mm and 4mm. The net force acting on the composite spring is 5000N. Find the force acting on each of the two springs.
Explanation: P₁/P₂=d₁²/d₂² and P₁+P₂=5000.
If the spring have same solid length and number of coils in the two springs are 8 and 10, then find the diameter of the spring with 8 coils. It is given diameter of spring with 10 coils is 12mm.
Two spring having stiffness constants of 22N/mm and 25N/mm are connected in parallel. They are to be replaced by a single spring to have same effect. The stiffness of that spring will be?
What will happen if stresses induced due to surge in the spring exceeds the endurance limit stress of the spring.
Explanation: If endurance limit is passed, fatigue failure will follow.
Surge is caused by resonance effect in the spring.
Explanation: When the natural frequency of vibrations of the spring coincides with frequency of external periodic force, resonance occurs.
Surge is a desirable effect in the sprigs.
Explanation: Surge means vibratory motion which isn’t welcomed anywhere in the machinery.
For a helical torsion sprig, the stress concentration factor at inner fibre is? Give spring index=5.
For a helical torsion sprig, the stress concentration factor at outer fibre is? Give spring index=5.
Spiral spring is quite rigid.
Explanation: Spiral spring is made of very thin wire which imparts great flexibility.
The strip of spiral spring is never subjected to pure bending moment.
Explanation: The strip of spiral spring is subjected to pure bending moment.
Calculate the bending stress induced in the strip of the helical spring. The spring is subjected to a moment of 1250N-mm with breadth and thickens of the strip being 11mm and 1.5mmm respectively.
Angle of rotation o arbour with respect to drum is given by?
Explanation: θ=ML/EI where I=btᵌ/12.