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Copyright © 2008 Altair Engineering, Inc. All rights reserved. Altair Proprietary and Confidential Information Free-Shape Optimization

Free shape panel_설명_v10

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Page 1: Free shape panel_설명_v10

Copyright © 2008 Altair Engineering, Inc. All rights reserved. Altair Proprietary and Confidential Information

Free-Shape Optimization

Page 2: Free shape panel_설명_v10

Copyright © 2008 Altair Engineering, Inc. All rights reserved. Altair Proprietary and Confidential Information

Free Shape Optimization

• No user-defined shape perturbation vector is necessary

• Reduce the effort to guess what would be the optimum shape

• Free Shape optimization uses a proprietary optimization technique developed by Altair, wherein the outer boundary of a structure is altered to meet with pre-defined objectives and constraints

• Can be combined with any type of optimization e.g. w/ morphing based shape optimization

Optimum

?

Page 3: Free shape panel_설명_v10

Copyright © 2008 Altair Engineering, Inc. All rights reserved. Altair Proprietary and Confidential Information

Free Shape Optimization

• DSHAPE card

Format

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)

DSHAPE ID

PERT DTYPE MVFACTOR NSMOOTH

GRID GID1 GID2 GID3 GID4 GID5 GID6 GID7

GID8 GID9 .… .…

Optional continuation line for grid constraints

(1) (2) (3) (4) (5) (6) (7) (8) (9)

GRIDCON GDID1 CTYPE1 CID1 X1 Y1 Z1

GDID2 CTYPE2 CID2 X2 Y2 Z2

…. …..

Page 4: Free shape panel_설명_v10

Copyright © 2008 Altair Engineering, Inc. All rights reserved. Altair Proprietary and Confidential Information

Free Shape Optimization

변형전

변형후

BOTH (default) GROW SHRINK

NOTE : Grow 또는 shrink와 같은 설계 범위제약조건이 요구되지 않으면, ‘Both’를 사용하는것을 추천함

• DTYPE – Free shape 영역 움직임의 방향을 제어하는 parameter

초기영역 내부로의이동이 없음

초기 영역 외부로의이동이 없음

Page 5: Free shape panel_설명_v10

Copyright © 2008 Altair Engineering, Inc. All rights reserved. Altair Proprietary and Confidential Information

Free Shape Optimization

• MVFACTOR – Free-Shape 설계 영역에서 정의한 grid들이 하나의 iteration에서이동할 수 있는 최대 이동 비율을 정의 (default = 0.5)

• Grid movement = MVFACTOR X 평균요소크기

• MVFACTOR를 작게 부여하면 free-shape optimization은 느리게 수행되지만 보다안정적이라는 이점이 있음

변형전 형상

MVFACTOR=1.0경우 iteration당 변화

MVFACTOR=0.5경우 iteration당 변화

Page 6: Free shape panel_설명_v10

Copyright © 2008 Altair Engineering, Inc. All rights reserved. Altair Proprietary and Confidential Information

Free Shape Optimization

(a) NSMOOTH = 5 (b) NSMOOTH = 1

NSMOOTH : Free-shape 최적화 요소 smooth를 위한 grid 층의 개수 (default=10)

Larger NSMOOTH : 요소 파괴를 피하는데 좋지만 느리게 최적화 속도가 느림

NSMOOTH can be larger than the number of available layers.

Page 7: Free shape panel_설명_v10

Copyright © 2008 Altair Engineering, Inc. All rights reserved. Altair Proprietary and Confidential Information

Free Shape Optimization

Constraint on GRID (Gridcon) – Grid의 움직임을 제어하는 parameter

1. FIXED – Free-shape 최적화 중 grid의 이동을 없게 만듬

2. VECTOR – 적용된 vector 방향으로 grid가 이동하도록 강제부여

3. PLANAR – Normal 방향으로 정의한 vector를 갖는 plane내에서만 grid가 움직임

Example

1. CTYPE=VECTOR

CTYPE 미정의

Vector 를 정의하여,

GRID의 이동을 고정함

Page 8: Free shape panel_설명_v10

Copyright © 2008 Altair Engineering, Inc. All rights reserved. Altair Proprietary and Confidential Information

Free Shape Optimization

2. CTYPE=PLANAR

Model Setup설계 Grid 정의

CTYPE 미정의Y방향으로 Shape 변경이 발생함

CTYPE=PLANER 정의(X-Z Plane)

Y 방향의 Shape

Change가 없음

Page 9: Free shape panel_설명_v10

Copyright © 2008 Altair Engineering, Inc. All rights reserved. Altair Proprietary and Confidential Information

Free Shape Optimization

1-plane Symmetry Constraint : 선택한 plane에 기준한 대칭 형상을 생성하는 parameter

Free-shape 설계 grid가정의된 2-d model

Symmetry constraint 가적용되지 않은 경우

Symmetry constraint를적용한 경우

Page 10: Free shape panel_설명_v10

Copyright © 2008 Altair Engineering, Inc. All rights reserved. Altair Proprietary and Confidential Information

Free Shape Optimization

Extrusion Constraint : 정의된 path를 따라 단면을 일정하게 유지하고자 할 때 사용

Extrusion Constraint가적용된 결과 예

Circular extrusion

path를 적용한 결과Extrusion Path를적용하지 않은 결과

Page 11: Free shape panel_설명_v10

Copyright © 2008 Altair Engineering, Inc. All rights reserved. Altair Proprietary and Confidential Information

Free Shape Optimization

Side Constraint : 선택한 두 좌표 (x1,y1,z1), (x2,y2,z2) 사이에서 최대 변위량 영역을정의하는 parameter. Range는 직교좌표, 원형좌표, 구형 좌표계에 따라서 결정됨

R1, R2 반경에 따른 Side

Constraint 적용 모델

Side Constraint를적용하여 얻은 결과

Side Constraint가적용되지 않은 결과 형상

Page 12: Free shape panel_설명_v10

Copyright © 2008 Altair Engineering, Inc. All rights reserved. Altair Proprietary and Confidential Information

Free Shape Optimization

Mesh Barrier Constraint : Special shell element (BMFACE)를 이용하여 수치적으로변형의 최소를 정의하는 효과를 부여하는 parameter

Mesh Barrier가적용된 형상

Mesh Barrier가적용되지 않은 결과

Mesh Barrier가적용된 결과

Mesh Barrier와1-Plane symmetry가 함께

적용된 결과

Page 13: Free shape panel_설명_v10

Copyright © 2008 Altair Engineering, Inc. All rights reserved. Altair Proprietary and Confidential Information

Free Shape optimization

P

Objective :

Minimize compliance

Subject to:

Volume < 4000.00

Page 14: Free shape panel_설명_v10

Copyright © 2008 Altair Engineering, Inc. All rights reserved. Altair Proprietary and Confidential Information

Free Shape optimization

DSHAPE 1

DSHAPE 2

Select Free Shape design grids

Page 15: Free shape panel_설명_v10

Copyright © 2008 Altair Engineering, Inc. All rights reserved. Altair Proprietary and Confidential Information

Free Shape optimization

Move only on X-Z plane – fix the height of the beam section

Page 16: Free shape panel_설명_v10

Copyright © 2008 Altair Engineering, Inc. All rights reserved. Altair Proprietary and Confidential Information

Free Shape optimization

ITER 0 : Compliance = 4.103E+00 Volume = 6.480E+03

Page 17: Free shape panel_설명_v10

Copyright © 2008 Altair Engineering, Inc. All rights reserved. Altair Proprietary and Confidential Information

Free Shape optimization

ITER 26 : Compliance = 3.368E+00 Volume=3.994E+03

Objective -17.91%, Max. constraint violation 62.00% 0.00%

Page 18: Free shape panel_설명_v10

Copyright © 2008 Altair Engineering, Inc. All rights reserved. Altair Proprietary and Confidential Information

Example 2: shape change history

Shape history of the solid beam example