CATIA 솔리드 모델링 1st 페이지 예제-07 (Multi-Body 이용 방법)_02

Tech/Product Concepts Covered (CATIA Multi-Body Solid Modeling)

• Multi-body modeling workflow (key idea): Build the parts that will be visible on the outside first, then create the internal “to-be-removed” shape by modifying/copying that outer set. The video emphasizes that using multiple bodies often reveals a repeatable pattern.

• Cavity body strategy:

  • First, create the remaining external geometry (example: torso body + cylinder parts).
  • Group those visible shapes into a single “cavity body.”
  • Then copy/paste the cavity body to create the geometry used for internal removal.

• Copy/Paste rules when duplicating a body (3 procedures mentioned):

  1. Rename the copied cavity body to “Core”.
  2. Hide the original part (note: the cavity body is already nested; hiding behavior effectively hides the higher-level part).
  3. When updating colors/geometry tied to the “core,” fillets connect, so only the fillet color/visual result changes.

• “Core body” reference / dotted line concept (“sluice line”):

  • The core body corresponds to a dotted reference line in the drawing (described like a “sluice line”).
  • Only regions recessed from the viewpoint of the core—specifically areas shown as dotted lines (front view + cross-section)—need modification.

• Dimensional operations for recessed thickness (Define F / Technics):

  • Using Define F on the core/main body to reduce thickness inward by 6mm.
  • Fillet-radius caveat: even if “4 sides reduced by 6mm” is stated, the corner fillet radius (r) may not automatically match.
  • The video explains how negative/adjusted radius values preserve the intended 3R fillet behavior:
    • If r is negative by 6mm, the 3R fillet remains.
    • If it becomes effectively 9 (negative minus 6 logic), the remaining fillet region changes and can create a different fillet outcome.

• Work order matters (tree structure):

  • The top step completes first, then subsequent operations proceed downward in the feature tree.
  • This affects visibility of fillets and how later edits apply.

• Display option important for editing speed (CATIA Infrastructure → Display tab):

  • Option: “Only the current appraised geometry area”
  • Effect: only the currently worked solid (the underlined one / currently active part) is displayed, making localized edits easier.

• Interaction with circular pattern (“Technics” + object pattern behavior):

  • If thickness reduction is defined after a circular pattern, it may require selecting multiple faces.
  • More efficient approach shown:
    • Define the pad/thickness change before applying the circular pattern so only one face needs editing.
  • The pattern later propagates the change because the circular pattern takes over the feature during its Technics state.

• Visibility/inspection technique using transparency:

  • After hiding/revealing bodies, the video uses:
    • Transparency at ~50% to make the core/cavity visible through the external geometry.
  • This helps confirm the shape to be removed inside using front view/cross-section cues.

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Tutorial Steps / Feature Construction (What the video builds)

• Create and copy internal “pocket” features:

  • Define inner removals at a height/depth of 6mm (example: cylindrical pocket section).
  • Hide/show relevant bodies while copying features.
  • Rename copied solids appropriately, including:
    • “Cylinder Pocket Body” (created by copying a portion of the top cylinder/core-side cavity logic).

• Pad subtraction with depth calculations:

  • Example logic:
    • Main body height starts at 60mm.
    • Remove 6mm + 6mm = 12mm, so 60 − 12 = 48mm used for placement.
  • Uses sign conventions (negative/positive values affect direction relative to the reference).

• Edge fillet behavior for inner transitions:

  • The video notes that applying an edge fillet after subtraction will cause cylinder-adjacent shapes to appear in the resulting geometry.

• Groove/circumferential feature replication:

  • To build grooves around side cylinders:
    • Copy the entire cylinder body (top + side cylinders) from the core side,
    • Insert/attach a duplicate onto a working “bottom”/target,
    • Hide the original cylinder core body during execution.
  • Groove dimensions discussed include:
    • Working from an existing “minus 12mm” thickness condition,
    • Determining additional thickness (example: +2mm),
    • Converting diameter/radius values (example: using radius derived from diameter change),
    • Using Technics values such as replacing -6mm with -4mm to finish groove work.

• Final merging/assembly logic:

  • Groove body is merged back into Core Body.
  • The final Core Body is described as consisting of:
    • Main Body + Cylinder Body (after modifications and merges).
  • Then the cavity/removal is finalized by “pulling out” the core toward the cavity result.

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Verification Methods Demonstrated

• Split function for cross-section check:

  • Uses surface-based Split to align a ZX plane direction with the arrow indicating the remaining/external shape.
  • After splitting, confirms internal thicknesses and offsets.

• Infinite plane section settings:

  • Uses “Infinite Plane”-type section.
  • Checks “Keep Major” and reports thickness measurements such as:
    • 2mm thickness on some sides
    • 3mm thickness on other sides
    • overall body thickness example 6mm
  • Confirms dimensions on the protruding and internal regions.

• Deactivation step (cleanup):

  • Runs a “Deactivate” once after the split cut (because it was done “for black purposes”).

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High-Level Takeaways (video’s conclusion)

• Core modeling principle: Divide into a multi-body structure, create the section 7 / first-page cavity-visible geometry first, then copy that body to create the internal removal core by modifying the copy.

• Mold-based manufacturing context (injection molding, casting/forging):

  • Mold cavities create external visible shape (cavity/mold side)
  • Internal hidden shape corresponds to the mold “mussel” side, analogous to the internal core being removed.

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Main Speakers/Sources

• The tutorial appears to be delivered by a single instructor (“I mentioned… let’s begin… now proceed…”), with no distinct second speaker identified in the subtitles.