Match List – l (Type of stress) with List – ll (Allowable value of stress) and select the correct answer using the codes given below the lists: (f y= minimum yield stress of steel) List – I List – II A. Axial tension 1. 0.75 f y B. Bending tension 2. 0.66 f y C. Maximum shear stress 3. 0.60 f y D. Bearing stress 4. 0.45 f y
A-3, B-2, C-4, D-1
Understanding Steel Stress Limits: Matching Types with Values
This question requires matching different types of stresses encountered in steel structures with their corresponding allowable stress values. These allowable values are typically defined as a fraction of the steel's minimum yield stress, denoted as $f_y$. We need to correctly pair each stress type from List I with its allowable limit from List II.
Matching Stress Categories with Allowable Limits
Based on common engineering practices and design codes, the following matches are established to determine the allowable stress limits for various conditions:
Axial Tension (A) - Allowable Stress $0.60 f_y$ (3)
When a steel member is subjected to a load pulling it equally along its length (axial tension), the maximum stress it can safely withstand is limited. For axial tension, the allowable stress is commonly taken as $0.60 f_y$.
Bending Tension (B) - Allowable Stress $0.66 f_y$ (2)
Bending tension occurs when a member is subjected to bending moments, causing tensile stresses on one side. While extreme fiber stress in bending is often limited to $0.75 f_y$, this specific matching indicates an allowable bending tensile stress of $0.66 f_y$ in this context.
Maximum Shear Stress (C) - Allowable Stress $0.45 f_y$ (4)
Shear stress arises from forces acting parallel to a surface. In structural steel design, particularly for elements like the web of beams or plates, the maximum allowable shear stress is typically limited to prevent shear failure. A commonly used value is $0.45 f_y$.
Bearing Stress (D) - Allowable Stress $0.75 f_y$ (1)
Bearing stress occurs at the contact surface between two parts when a load is applied. This is common in connections where members rest on or bear against each other. The allowable bearing stress is generally set at a higher value, often $0.75 f_y$, reflecting the nature of this stress distribution.
Final Correct Matching
Synthesizing these points, the correct matching between the type of stress and its allowable value is:
- A. Axial tension - 3. $0.60 f_y$
- B. Bending tension - 2. $0.66 f_y$
- C. Maximum shear stress - 4. $0.45 f_y$
- D. Bearing stress - 1. $0.75 f_y$
This corresponds to option 3.
Important Questions from Riveted Connections
As per IS 800, the efficiency of a riveted joint having the minimum pitch is:
As per IS 800, the minimum pitch of rivets in a row is recommended as:
The distance between the centre of two consecutive rivets measured along a row of rivets is known as ______.
If the working stress in bearing in power driven rivets is 300 N/mm2 and a double riveted double cover butt joint is used to connect plates of 12 mm thick, then the strength of rivet in bearing is
(Given: The nominal diameter of rivet = 22 mm)
As per IS:800-1984, the minimum pitch of rivets in a row is recommended as the diameter of the rivet times
