Recent changes to ExampleCable2

ExampleCable2 modified by A. Vontobel

A. Vontobel — Sun, 11 Sep 2016 21:55:40 -0000

--- v4
+++ v5
@@ -2,7 +2,7 @@

     #! drawj2d -T svg -r96 -W 150 -H 60 -X 30 -Y 20 ExampleCable2.hcl

-    unitlength [/ 1000. 50.]
+    unitlength [/ 1. 50.] m
     forceunitlength 1

     # bearings

ExampleCable2 modified by A. Vontobel

A. Vontobel — Tue, 10 Nov 2015 00:26:45 -0000

--- v3
+++ v4
@@ -50,8 +50,9 @@
     set C4 [XY [stat.move $Q4 [XY $F3] [stat.tip $F3]]]; point $C4
     set C5 [XY [stat.move $Q5 [XY $F4] [stat.tip $F4]]]; point $C5
     line $A $C1 $C2 $C3 $C4 $C5 $B
-    moveto $A; assert "abs([stat.moment $F5] - [stat.moment $F5]) < 10^-7" {check F5 = FB}
-    assert "abs([stat.abs $F5] - [stat.abs $F5]) < 10^-7" {check F5 = FB}
+    moveto $A; # verify the forces F5 and FB are equal
+    assert "[stat.moment $F5] ~= [stat.moment $FB]" {moment check F5 = FB}
+    assert "[stat.abs $F5] ~= [stat.abs $FB]" {check F5 = FB}

     # force polygon
     moveto 5 0; set posPolygon [here]
@@ -65,5 +66,5 @@
     texforce [FXY $FA] F_A
     texforce [FXY $FB] F_B
     # verify the force polygon is closed
-    assert "[nf [geom.distance $posPolygon] 9] = 0" {equilibrium check}
+    assert "[geom.distance $posPolygon] ~= 0" {equilibrium check}

ExampleCable2 modified by A. Vontobel

A. Vontobel — Tue, 18 Aug 2015 23:14:39 -0000

--- v2
+++ v3
@@ -1,3 +1,4 @@
+[[img src=out-ExampleCable2.svg alt="Drawj2d output"]]

     #! drawj2d -T svg -r96 -W 150 -H 60 -X 30 -Y 20 ExampleCable2.hcl

@@ -66,5 +67,3 @@
     # verify the force polygon is closed
     assert "[nf [geom.distance $posPolygon] 9] = 0" {equilibrium check}

-
-[[img src=out-ExampleCable2.svg alt="Drawj2d output"]]

ExampleCable2 modified by a v

a v — Sat, 02 May 2015 23:48:38 -0000

--- v1
+++ v2
@@ -1,4 +1,3 @@
-

     #! drawj2d -T svg -r96 -W 150 -H 60 -X 30 -Y 20 ExampleCable2.hcl

ExampleCable2 modified by a v

a v — Sat, 02 May 2015 23:48:11 -0000

#! drawj2d -T svg -r96 -W 150 -H 60 -X 30 -Y 20 ExampleCable2.hcl

unitlength [/ 1000. 50.]
forceunitlength 1

# bearings
set A {0 0}; dot $A; lb A SW
set B {3.0 0}; dot $B; lb B SE
# cable angle at A
set alpha 35

# forces acting on the cable
pen blue 0.35
set Q1 "0.5 0  0 5";  force2 $Q1
set Q2 "1.0 0  0 7";  force2 $Q2
set Q3 "1.5 0  3 12"; force2 $Q3
set Q4 "2.0 0  0 6";  force2 $Q4
set Q5 "2.5 0  0 4";  force2 $Q5

# resultant
set R [stat.add $Q1 $Q2 $Q3 $Q4 $Q5]
set C [XY [stat.move $R $A [++ $A [geom.polar $alpha]]]]
pen dashed gray
point $C; lb C SW
line $A $C $B

# global moment equilibrium at pos. B in order to get force FA
pen solid green
moveto $B
set fA "$A  [geom.polar $alpha]"
set FA [stat.mequi $fA $R]
force $FA
# equilibrium to get force FB
set FB [stat.equi $R $FA]
set FB [stat.move $FB $A $B]; # move along action line
force $FB

# cable geometry
pen
set F1 [stat.equi $FA $Q1]
set F2 [--- $F1 $Q2]
set F3 [--- $F2 $Q3]
set F4 [--- $F3 $Q4]
set F5 [--- $F4 $Q5]
set C1 [XY [stat.move $Q1 [XY $FA] [stat.tip $FA]]]; point $C1
set C2 [XY [stat.move $Q2 [XY $F1] [stat.tip $F1]]]; point $C2
set C3 [XY [stat.move $Q3 [XY $F2] [stat.tip $F2]]]; point $C3
set C4 [XY [stat.move $Q4 [XY $F3] [stat.tip $F3]]]; point $C4
set C5 [XY [stat.move $Q5 [XY $F4] [stat.tip $F4]]]; point $C5
line $A $C1 $C2 $C3 $C4 $C5 $B
moveto $A; assert "abs([stat.moment $F5] - [stat.moment $F5]) < 10^-7" {check F5 = FB}
assert "abs([stat.abs $F5] - [stat.abs $F5]) < 10^-7" {check F5 = FB}

# force polygon
moveto 5 0; set posPolygon [here]
pen blue 0.3; font 3
texforce [FXY $Q5] Q5
texforce [FXY $Q4] Q4
texforce [FXY $Q3] Q3
texforce [FXY $Q2] Q2
texforce [FXY $Q1] Q1
pen green
texforce [FXY $FA] F_A
texforce [FXY $FB] F_B
# verify the force polygon is closed
assert "[nf [geom.distance $posPolygon] 9] = 0" {equilibrium check}