CATIA INTERVIEW QUESTION NO: 0001

                           HERE IS A ANOTHER SET OF INTERVIEW QUESTIONS NO : 0001


LEVEL : INTERMEDIATE

SOURCE : http://tinyurl.com/o8cg5rg

• What is CATIA? What are the different modules of CATIA? What are the main Features of CATIA?

CATIA: Computer Aided Three Dimensional Interactive Applications.

It is used to create three-dimensional geometric models using wire frame, surface and solid modeling constructions.

Additional application modules incorporated with CATIA provide

Capabilities for:

• Kinematics
• Robotics
• FEM mesh generation
• FEM Solutions
• NC Mill
• NC Lathe Programming
• Piping Design
• Structural Member Design and
• Image Generation

 

Additional Module allows data exchange between CATIA and other application and provide an internal CATIA mathematical routines and user interface.

Main Features of CATIA are:

• Maintains a full three-dimensional data base
• Allows direct construction of 3D Wire frame and Solid Module
• 3D space elements and 2D draw elements can co-exist simultaneously in the same model
• Automatic generation of machining instruction to drive an NC tool
• Geometry interface which can accept geometry from other system and analysis programs as well as extract data for delivery to other systems
• Kinematics module which simulates the movement of part in space
• Robotics module to simulate a robots work envelope

 

• What are the relations b/w SURFACE, FACE, SKIN and VOLUME?
  

SURFACE:

• A Surface is an infinitely thin, mathematically defined contoured area in space .It is displayed visually by isoperimetric curves and boundary curves.
• In simple terms a surface is an entity that has length and width, but essentially no thickness.
• In CATIA Surface is a Parent element for Face and Skin.

 

FACE:

• It is a portion on a surface defined with curves as boundaries or it is a portion in a plane defined with curves or lines as boundaries.
• Face is a child of surface

 

SKIN:

• A skin is a set of joined faces, surfaces, skins, or volumes, similar to the volume, but with a single domain and without closure condition.
  In addition, an offset can be associated with each of the faces.

 

VOLUME:

• A Volume is a set of joined faces or surface or skins or volume, with total closed domains.
• While creating Volume the order of selecting the faces is important. Also a Volume can have an inner domain.

 

• What is the difference between SOLID EXACT and SOLID MOCK-UP?

 

SL. NO.	SOLID EXACT	SOLID MOCK-UP
1	Exact solids manipulate an exact type, that is, a non-approximated boundary representation.	Mock-up solids manipulate an approximated type B-Rep, that is, a representation resulting from an approximation of the non-planar forms by planar facets.
2	They are distinguished by having precisely defined surface definition.	They incorporate surfaces that are approximated using discrete planar facts.
3	They can be used for all other CATIA operations including NC programming.	They can be used effectively for object visualization, constructing mock-up to validate assembly operations or for kinematics, dynamic and FEM analysis
4	These models have applications in more artistic situations with highly contoured surfaces. Note: All curves are displayed as poly lines with decartelization being determined to achieve the most realistic appearance without excessive computational effort.	These models are simple but are of little value for applications requiring precise surface definition.

 

• What is the difference between PRIMITIVE and FEATURE?
  PRIMITIVE:
  It is generally the simplest solid elements that can be create.
  The three types of primitives are:
  • Canonical Primitives:    
    • Defined by geometric values:    
      Parallelepiped
      Cylinder
      Cone
      Sphere
      Torus
    • Defined by contour and geometry values:
      
      Revolution: elements obtained by rotating an open or
      Closed profile about an axis.
      Sweep: elements obtained by sliding contour along a spine while the normal to the contour plane remains parallel to the tangent to spine.
      From skin surfaces or non-planar faces by
      Closing through offsetting the same surfaces.
      Closing through projection onto a plane.
      Closing using planar faces.

 

 

• Macro Primitives:
  Macro primitives are SOL type elements obtained from dittos (DIT type elements).
  The corresponding detail has SOL type elements itself.

 

FEATURE:

• A feature is a set of user defined technological object consisting of:
  • Geometry
  • Parametric definition and
  • Technological attributes
• Normally, features are characterization details of a part that have a strong correspondence or linkage to a particular manufacturing process.
  (Ex: a counter bored hole, a boss around a hole, a pocket)
• Features are defined by the user or the administrator, stored in the library and used to create parts of features, compound features.

 

• What is the difference between SOLIDE+MODIFY+OPERATION+DUPLICATE and TRANSFORM+SYMMETRY?
  The first difference between these two operations is that with the SOLIDE+ MODIFY+OPERATION, you must first indicate whether or not this is going to be duplication or replacement. The second major difference between TRANSFORM and MODIFY+OPERATION+DUPLICATE is that transform keeps a link between the originating primitives where MODIFY+OPERATION+DUPLICATE does not. In other words, with transform, if a change is made to the originating solid, the copied solids will also change.

 

• What is the difference between SURF1+GEOEXTR and LIMIT2+SURFACE+EXTRAPOLATE?

SURF1+GEOEXTR	LIMIT2+SURFACE+EXTRAPOLATE
Extrapolated surface will not be having the same deviation and degree of the original surface but is tangent only to the one side of the surface. (i.e., straight segment surface)	Extrapolated surface will be having the same Shape, deviation and degree of original surface.
Surface generated through extrapolation is separate entity with original surface and needs concatenation of surfaces.	The resultant surface after extrapolation is single surface. (i.e., automatically concatenated)

 

• What is the use of part Editor Window?
  Part editor allows visualization and real time modification of your designed part by selecting or directly acting on the feature structure of the part.

 

• What are contextual menu and its applications?
  Clicking on a branch or feature displays the corresponding contextual menu. This tool help you get commonly used operations faster such as:
  • Color: to change the color of the solid
  • Parent: to manage the parents of the element
  • Delete: to delete the element (=delete no keep)
  • Break: to separate one branch from the whole solid (=delete keep)
  • Active/Inactive: to activate or inactivate the element
    (or only fillets or drafts of the branch)
  • Collapse/Expand: to reduce a whole branch to single component
    (Or vice versa) such as a group of holes
  • Smart/Unsmart: to active or deactivate smart solid.
  Also in part editor, their two types of feature lists can be possible.

1. Simplified view of feature list:
2. Detailed view of feature list :- internal views of feature branches and macro primitives are displayed.

 

• What is model?

        A Model is an individual drawing, read into main memory for interactive processing.

Model can contain one or more workspaces which in turn can contain one or 4more sets with zero or more elements in each.

 

• What are the functions of FORMTOOL?
  • Form tool allows performing semiautomatic filleting, trimming and breaking operation on a shape with sharp edges.

• Form tool creates surface, face and skin in a single interaction
  • Skins are the main tool of the Form tool function since they allow us to combine faces and consider them as a single entity.
• Form tool allows creating variable radius fillet.
  
   
  • What is the use of LAW function and where is its application?
    
            The purposes of a law are easy to understand, but its application may be more complex. Laws involve the creation of geometry to control different aspects of a surface. A surface may be controlled by aspects of area, radius (width) or angle. Depending on the transitions that need to make another surface element, users may need to develop 2 dimension wire frame that will dictate how the transition is to be made in ratio proportion to the application of the law geometry. It sounds a lot harder than it is use.
  
   
  • What are sets?
    
          A set is a disjoint group of elements of different types that can be processed together
  
   
  • What is an element?
    
        Elements are the lowest level geometry entity created by their corresponding functions.
  
   
  • 
    What is the session?
    
      Session is a set of models.
  Session is used to allow two or more models to be positioned to create a more complex assembly.
  A Session can contain several 'passive' Models but only a single 'Active' Model, which is the model displayed in the CATIA      workspace.
  A Session is defined by a set of models and a SESSION MANAGER.
  The SESSION MANAGER configures a CATIA session and manages the data
  Working with a session is working in contest; this allows you to visualize your digital mock-up and to perform various simulations.
  A session is stored in a SESSION-type file. It must be considered as a temporary work environment save.     
  No data transfer capability is provided on a session.
  
   
  
   
  
   
  • What is workspace? What is the difference b/w Master and Detail Workspace?    
         Each Model can have one MASTER workspace which is the area in which the model     is created and manipulated. In addition, a model can have zero or more workspace called DETAIL workspace. These are auxiliary workspace that contains elements that are to be duplicated to several locations in the MASTER workspace. In addition, DETAIL workspace can also be organized into separate library files using the LIBRARY Function. These can be shared with many models to allow organizational standardization.
    
     
    16. Is it necessary to break cylindrical surface along vertically for generation of faces?
      No need to break the surface because the catia itself automatically create two faces along circumference.
  
  
  
   What is the difference b/w SPACE mode and DRAW mode?
      SPACE MODE:
  a. In space Mode, it is possible but often quite awkward to work directly in the 3D Space. Ex:
       Entering points that lie in a plane can be tedious when three coordinates must be entered for
  each point.
  b. In Space Mod e, CATIA allows the user to temporarily switch into a 2D mode to create,
       view or manipulate elements.
  c. The 2D Mode is very convenient for working with 3D Geometry in the Space Mode of
       operation.
  
   
      DRAW MODE:

1. The Draw Mode of operation is purely 2D Mode in which CATIA can be used for
       the drafting purpose.
2. The geometry is 2D only but can be organized into up to 255 views. Each view can
       be defined by a geometry transformation with respect to another view. In this way, it
       is possible to create a multi view orthographic projectio0n engineering drawing.
3. The Draw Mode can be used independently or it can be used to project a full 3D
       Model into Multiple Orthographic projection for purpose of preparing a traditional
       engineering drawing. This process is referred as CATIA Draw/Space Integration and
       is managed by special CATIA functions.
4. The Draw Mode is probably the most useful way to generate paper copies of a
       CATIA Model for engineering purposes.

 

         What is the difference b/w

1. DITTO,COPY and TRANSFER options in DETAIL function
2. HELIC Pitch and Redial Pitch in SURF+REVOLUN+UNSPEC
3. PT type element and CST type element.
4. ARC and SPLINE
5. CUR1+COMBINE and CURV 1+PROJECT

Follow the blog to get more updates

Learn CATIA faster and easier. To know more click here