Strength Of Materials MCQ Questions & Answers | Mechanical Engineering

A lap joint can experience both single and double shear.

In a single shear lap joint, the forces act in a single plane, and the joint is subjected to shear along one plane only.
In a double shear lap joint, the forces are distributed over two planes, effectively reducing the shear stress in each plane.

Therefore, the correct answer is Option C: Both A and B.

The correct answer is Option B: Less than

Here's why:

In mechanical engineering, specifically in the study of pressure vessels, we categorize them as either "thin shells" or "thick shells" based on the ratio of their wall thickness (t) to their inner diameter (D).

A pressure vessel is considered a thin shell when the wall thickness is relatively small compared to its diameter. This allows us to make certain simplifying assumptions in our calculations of stress and strain.

The generally accepted criterion is:

If t/D < 1/10, then the vessel is considered a thin shell. This means the wall thickness (t) must be less than one-tenth of the diameter (D). If the wall thickness is too large compared to the diameter (t/D >= 1/10), it's considered a thick shell, and different, more complex formulas are needed.

* Slenderness Ratio: This is a way to measure how likely a column is to buckle (bend sideways) under a load. It's calculated by dividing the column's effective length by its least radius of gyration.

* Short Columns: These are columns that are relatively stocky. They tend to fail due to crushing (the material being squeezed) rather than buckling.

* Long Columns: These are columns that are relatively slender. They are more likely to buckle under load.

* Medium Columns:These columns behaviour lies between short and long columns.

* General Rule: A common rule of thumb is that columns with a slenderness ratio less than 80 are generally classified as short columns. They primarily fail due to compressive stresses exceeding the material's yield strength.

* Weak Columns: This term isn't directly related to slenderness ratio in the same defining way as short or long columns. A weak column could be weak due to material properties or manufacturing defects, regardless of its slenderness ratio.

Therefore, a slenderness ratio less than 80 indicates a short column that's prone to crushing rather than buckling.