Presentation is loading. Please wait.

Presentation is loading. Please wait.

Motion and Stress Analysis by Vector Mechanics Edward C. Ting Professor Emeritus of Applied Mechanics Purdue University, West Lafayette, IN National Central.

Similar presentations


Presentation on theme: "Motion and Stress Analysis by Vector Mechanics Edward C. Ting Professor Emeritus of Applied Mechanics Purdue University, West Lafayette, IN National Central."— Presentation transcript:

1 Motion and Stress Analysis by Vector Mechanics Edward C. Ting Professor Emeritus of Applied Mechanics Purdue University, West Lafayette, IN National Central University, ChungLi, Taiwan

2 a computer framework for the study of a multi-component structural system with component motion component interactions: connection, contact, collision, penetration geometrical changes: deformation, displacement, fragmentation, collapse stress distribution behavior and material property changes

3

4

5

6 a physics approach of mechanics motion analysis and VFIFE * vector mechanics ---- particle mechanics * discrete description * intrinsic finite element ---- physical structural element

7 example: a rod in plane motion Newton’s law 1. displacement is a motion

8 analytical mechanics: For motion analysis, assume 1. rigid body, 2. functional description

9 pendulum problem: hinged at end 1 motion analysis 1. general formulation: 2. complete formulation :

10 stress analysis assume: 1. deformable body, 2. Hooke’s law

11 1. An approximation → separate motion analysis and stress analysis ► continuous bodies: motion--rigid body; stress--deformable body ► variables: motion--displacement; stress--deformation ► governing equations: motion--translation and rotation; stress--equilibrium 2. Described by continuous functions → discretization computation based on analytical mechanics

12 1. Newton’s law 2. behavior model 3. kinematics 4. Hooke’s law 5. pendulum: constraint conditions hinged end: straight rod: vector mechanics

13 properties: 1. structure: a set of particles 2. always a dynamic process 3. always deformable advantages: 1. suitable for computation 2. a general and systematic formulation 3. explicit constraint conditions

14 development needs: 1. describe structural geometry: intrinsic finite element 2. kinematics: fictitious reversed motion 3. continuity requirements 4. mechanics requirements 5. material model: standard tests elements: plane rod, plane frame, plane solid, space rod, space frame, 3d membrane, 3d solid, 3d plate shell V-5 research group: e. c. ting, c. y. wang, t. y. wu, r. z. wang, c. j. chuang

15 motion analysis procedure: a simple rod structure

16 discrete model: mass particles and structural elements

17 vector form equation of motion

18 path element 1. element geometry remains unchanged 2. small deformation discrete path:

19 kinematics and force calculation 1 material frame: configuration at 2. variable: nodal deformation 3. fictitious reversed motion to define deformation 4. infinitesimal strain and engineering stress 5. nodal forces: use finite element 6. internal forces are in equilibrium

20 reversed motion for nodal deformation

21

22 governing equations

23 difference equation (symmetrical case)

24 ,

25 4 node plane solid element

26 estimate the rigid body motion

27 fictitious reversed motion

28 nodal deformation

29 deformation coordinates to define independent variables

30 shape functions:

31

32

33 nodal forces

34

35 stress

36

37

38

39

40

41

42

43

44

45

46

47

48

49

50

51 Thank You


Download ppt "Motion and Stress Analysis by Vector Mechanics Edward C. Ting Professor Emeritus of Applied Mechanics Purdue University, West Lafayette, IN National Central."

Similar presentations


Ads by Google