In 3D CAD and engineering graphics, which solid type results from sweeping a 2D profile along a straight (linear) path?
-
APlanar solid
-
BRevolved solid
-
CWarped solid
-
DExtruded solid
Answer
Correct Answer: Extruded solid
Explanation
Introduction / Context:Feature-based modeling creates solids by transforming 2D profiles. Two fundamental operations are revolve (around an axis) and extrude (along a path). Understanding which operation yields which result is essential for accurate modeling.
Given Data / Assumptions:
- A 2D closed profile (e.g., rectangle, circle, polyline) is available.
- The path is linear (straight line in a specified direction).
- We want the standard solid generated by this operation.
Concept / Approach:Extrusion moves a profile a specified distance along a direction, creating a prismatic solid whose cross-section matches the profile. This is distinct from revolve, which rotates a profile about an axis to produce a solid of revolution (e.g., shafts, pulleys).
Step-by-Step Solution:
Choose the 2D profile and ensure it is closed for a solid result.Specify the linear direction and distance.Apply the extrude command to generate the solid.Optionally add taper or draft if supported by the tool.Validate mass properties and dimensions.Verification / Alternative check:Section the model perpendicular to the extrusion direction; the cross-section should match the original 2D profile exactly. Measuring the model length should equal the extrusion distance.
Why Other Options Are Wrong:
- Planar solid: Not a standard term for this operation.
- Revolved solid: Requires rotation about an axis, not a straight sweep.
- Warped solid: Implies a nonplanar or twisted surface, not a linear extrusion.
Common Pitfalls:Extruding an open profile yields a surface, not a solid. Ensure the sketch is closed and lies on a plane.
Final Answer:Extruded solid