Section,Development And Interpenetration Of Solids

 The principles Of Projections of solids.

1. Section Of Solids.


2. Development.


3. Intersections.

Sectioning a solid

An object (here solid) is cut by some imaginary cutting plane to understand the internal details of that object.

• The action of cutting is called Sectioning a solid & The plane of cutting is called Section plane.

Two cutting actions means section planes are recommended.

Section Plane Perpendicular To Vp And Inclined To Hp.

(This Is a Definition Of An Aux. Inclined Plane i.e. A.I.P.)

Note:- This Section Plane Appears as a Straight Line In FV.

Section Plane Perpendicular To Hp And Inclined To Vp.

( This Is a Definition Of an Aux. Vertical plane i.e. A.V.P.)

Note:- This Section Plane Appears as a Straight Line In TV.

Remember:-

After Launching a Section Plane Either In FV or TV, The Part Towards Observer Is Assumed To Be Removed. As Far As Possible the Smaller Part  Is Assumed To Be Removed.

Illustration Showing Important Terms In sectioning.

Typical Section Planes And Typical Shapes Of Sections

Development Of Lateral Surfaces Of Different Solids.

Development Of Surfaces Of Solids.

Meaning:

Assume Object Hollow And Made-Up Of Thin Sheet. Cut open it from one side and Unfold the sheet Completely. then the shape of that unfolded sheet is called the Development of lateral surfaces of that object or solid.

Lateral surface is the surface excluding solid's top & base.

Engineering Application:

There are so many products or objects which are difficult to manufacture by Conventional Manufacturing Processes, because of their shapes and sizes.

those are fabricated in sheet metal industry by using the Development technique. there is a vast range of such objects.

Examples:

Boiler shells & Chimneys, pressure vessels, shovels, trays, boxes & cartons, feeding hoppers, large pipe section, body & parts Of automobiles, ships, airplanes, and many more.

What Is Our objective in this topic?

• To learn methods of development of surface of different solids, their sections, and frustums.

Note the following Important points.

1. Development is a different drawing than PROJECTIONS.


2. It is a shape showing area, which means it's a 2-d plain drawing.


3. Hence all dimensions of it must be true dimensions.


4. As it is representing the shape of an-un -folded sheet, no edges can remain hidden, and hence dotted lines are never shown on development.

Internet action of solids ( Intersections )

When one solid penetrates another solid then their surfaces intersect

And

At the junction of the intersection, a typical survey is formed, Which remains common to both solids. This curve is called the curve of intersection

And

 It is a result of the interpenetration of solids.

Purpose of drawing these curves:

 When two objects are to be joined together maximum surface contact between both becomes a basic requirement for the strongest & leak-proof joint.

curves of intersections being common to both intersecting solid, show exact & maximum surface contact of both solids.

Study Following Illustrations Carefully.

Some Actual Objects are Shown, Showing Curves Of Intersections. By white Arrows.

Please write comments if you find anything incorrect and if you have any queries about this topic or you want to share more information about the topic discussed above.