This chapter discusses line models and contains three exercises: 1) A flexible gripper made of POM with 7 points is modeled and its output displacement converges with increasing elements. 2) A 3D truss tower with 25 joints is designed to withstand specified loads. 3) A two-story building with steel beams, concrete slabs, and 10-foot floors is modeled using lines, surfaces and engineering data.

1. Chapter 7 Line Models 1
Chapter 7
Line Models
7.1 Step-by-Step: Flexible Gripper
7.2 Step-by-Step: 3D Truss
7.3 More Exercise: Two-Story Building
7.4 Review

2. Chapter 7 Line Models Section 7.1 Flexible Gripper 2
Section 7.1
Flexible Gripper
Problem Description
[3] Actuation
direction (input).
[2] The ends are
connected to a rigid
ground (preventing
translations and
rotations).
[4] Gripping
direction
(output).
[1] The gripper is
made of POM.
P1(−70,0)
P2(−90,40)
P3(−69,120)
P4(−35,160)
P5(−34,100)
P6(−24,60)
P7(0,50)
X
Y

3. Chapter 7 Line Models Section 7.1 Flexible Gripper 3
Techniques/Concepts
• Line bodies
• Cross Sections
• Cross Section Alignments
• Cross Section Solids
• Beam Elements
• Symmetry Conditions
• Geometric Advantage
0
10
20
30
40
50
60
0 5 10 15 20 25 30 35 40 45 50
HorizontalDisplacement(mm)
Input Displacement (mm)

4. Chapter 7 Line Models Section 7.1 Flexible Gripper 4
52.24
52.26
52.28
52.30
52.32
0 125 250 375 500 625
OutputDisplacement(mm)
Number of Elements
Convergence Study of Beam Elements
[1] In this exercise, we
meshed with 34
elements, resulting 52.335
mm of displacement.
[2] The displacement
converges to 52.381 mm.

5. Chapter 7 Line Models Section 7.2 3D Truss 5
200"
200"
75"
P1P2
P3
P4
P5 P6
P7
P8
P9 P10
1
2
3 4
5
67 89
10
11
12
13
14
15
16
17
1819
20
21
22
23
24
25
100"100"
X
Y
Z
75"
Section 7.2
3D Truss
Problem Description
Design Loads for the Transmission Tower
Joint FX (lb) FY (lb) FZ (lb)
P1 1,000 -10,000 -10,000
P2 0 -10,000 -10,000
P3 500 0 0
P6 600 0 0

6. Chapter 7 Line Models Section 7.2 3D Truss 6
Techniques/Concepts
• Create points
• Concepts>Lines From Points
• Convergence of straight beam
elements

7. Chapter 7 Line Models Section 7.3 Two-Story Building 7
Section 7.3
Two-Story Building
Problem Description
[1] All beams and
columns are made
of structural steel,
with a cross
section of W16x50. [2] The floor slabs
are made of reinforced
concrete, with a
thickness of 5".
[3] Each
floor-to-floor
height is 10'.
20'
20' 20'20'

8. Chapter 7 Line Models Section 7.3 Two-Story Building 8
Techniques/Concepts
• Adjust Cross Section
Alignments
• Concepts>Surface From
Edges
• Use of Selection Panes
• Flip Surface Normal
• Form New Part
• Import Engineering Data
• Inertial>Standard Earth
Gravity
• Inertial>Acceleration