BAB IV APLIKASI ANALISA P C
ollapse PADA GABLE FRAME
4.1. Aplikasi Perhitungan
Dalam tugas akhir ini maka diberikan suatu contoh perhitungan untuk mencari factor beban runtuhnya collapse load factor,
�
�
akibat struktur mengalami mekanisme keruntuhan dengan jumlah sendi plastis yang terbentuk
sebelum mengalami keruntuhan. Selain itu beban runtuh Pkritis dapat diperoleh dengan melacak keadaan pembebanan portal dan dengan melakukan analisa
elastis pada struktur yang dimodifikasi akibat terbentuknya sendi plastis yang baru dengan jumlah sendi palstis yang diijinkan sebelum mengalami keruntuhan. beban
runtuh Pkritis dan factor beban runtuhnya collapse load factor, �
�
akan diperoleh dengan metode finite element. Untuk perhitungan tabel-tabel dilakukan
dengan bantuan program Microsoft Excel 2007. Data-data yang digunakan dalam aplikasi adalah sebagai berikut :
Gambar 4.1. Struktur gable frame dan pembebanannya
4Pc
Pc 3Pc
a b
c d
h
1
h
2
h
3
h
4
h
5
h
6
h
7
b a
c d
e f
g
10m 1
2 3
4 5
6 7
8
10m 20m
10m 10m
3m 3m
10m 6m
3m
17m
Universitas Sumatera Utara
4.2. Data- data struktur
• Langkah I : menentukan model yaitu nomor simpul dan element � = 4175000 ��
2
Element I m
4
��
�
L m �
Kuadran ��� �
��� �
a 0.1440
0.2044 10
90 I
1.000 0.000
b
0.1440 0.2044
10 90
I 1.000
0.000
c
0.2464 0.3266
10.44 16.69
I 0.287
0.958
d 0.2464
0.3266 10.44
16.69 I
0.287 0.958
e 0.1934
0.2653 20.88
343.31 IV
-0.287 0.958
f
0.1934 0.2653
10.44 343.31
IV -0.287
0.958
g
0.1140 0.1716
17 270
III -1.000
0.000
Element
���
�
� ���
�
� ��� � ��� � ��
� ����
�
�
��� �
�
a 1.000
0.000 0.000
85337 7214.4
36072
b 1.000
0.000 0.000
85337 7214.4
36072
c 0.082
0.918 0.275
130608.716 10848.68085
56630.114
d 0.082
0.918 0.275
130608.716 10848.68085
56630.114
e 0.082
0.918 -0.275
53047.2941 1064.394723
11112.281
f
0.082 0.918
-0.275 106094.588
8515.157781 44449.124
g 1.000
0.000 0.000
42142.9412 1162.507633
9881.3149
Universitas Sumatera Utara
Element
��� �
��� �
� �
���
�
+ ���
�
�
�
�
� �
� ���
�
+ ���
�
�
�
�
� �
� �� −
��� �
�
� ��
a 240480
120240 7214.400
85337.000 0.000
b 240480
120240 7214.400
85337.000 0.000
c 394145.594
197072.797 120730.907
20726.491 32945.344
d 394145.594
197072.797 120730.907
20726.491 32945.344
e 154682.95
77341.4751 48759.744
5351.945 -14300.217
f 309365.9
154682.95 98046.235
16563.511 -26843.579
g 111988.235
55994.1176 1162.508
42142.941 0.000
Element
��� �
�
� ���
�
�
� Ujung
batang Kapasitas momen
plastis Mp
a
36072 0.000
1 765.0
2 765.0
b 36072
0.000 1
765.0 2
765.0
c 16263.792
54244.437 1
1275.0 2
1275.0
d 16263.792
54244.437 1
1275.0 2
1275.0
e
-3191.3731 10644.150
1 1015.0
2 1015.0
f -12765.492
42576.599 1
1015.0 2
1015.0
g
-9881.3149 0.000
1 616.0
2 616.0
Universitas Sumatera Utara
• Langkah II : menentukan matriks kekakuan lokal element
[ �] =
⎣ ⎢
⎢ ⎢
⎢ ⎢
⎢ ⎢
⎢ ⎡
�� �
12 �� �
3
6 �� �
2
6 �� �
2
4 �� �
−
�� �
−
12 �� �
3
6 �� �
2
−
6 �� �
2
2 �� �
−
�� �
−
12 �� �
3
−
6 �� �
2
6 �� �
2
2 �� �
�� �
12 �� �
3
−
6 �� �
2
−
6 �� �
2
4 �� �
⎦ ⎥
⎥ ⎥
⎥ ⎥
⎥ ⎥
⎥ ⎤
Element a :
[ �
�
] = ⎣
⎢ ⎢
⎢ ⎢
⎡ 85337.00
0.00 0.00
−85337.00 0.00
0.00 0.00
7214.40 36072.00
0.00 7214.40
36072.00 0.00
36072.00 240480.00
0.00 −36072.00
120240.00 −85337.00
0.00 0.00
85337.00 0.00
0.00 0.00
−7214.40 −36072.00
0.00 7214.40
−36072.00 0.00
36072.00 120240.00
0.00 −36072.00
240480.00 ⎦
⎥ ⎥
⎥ ⎥
⎤
Element b :
[ �
�
] = ⎣
⎢ ⎢
⎢ ⎢
⎡ 85337.00
0.00 0.00
−85337.00 0.00
0.00 0.00
7214.40 36072.00
0.00 −7214.40
36072.00 0.00
36072.00 240480.00
0.00 −36072.00
120240.00 −85337.00
0.00 0.00
85337.00 0.00
0.00 0.00
−7214.40 −36072.00
0.00 7214.40
−36072.00 0.00
36072.00 120240.00
0.00 −36072.00
240480.00 ⎦
⎥ ⎥
⎥ ⎥
⎤
Element c :
[ �
�
] = ⎣
⎢ ⎢
⎢ ⎢
⎡ 130608.72
0.00 0.00
−130608.72 0.00
0.00 0.00
10848.68 56630.11
0.00 10848.68
56630.11 0.00
56630.11 394145.59
0.00 −56630.11
197072.80 −130608.72
0.00 0.00
130608.72 0.00
0.00 0.00
−10848.68 −56630.11
0.00 10848.68
−56630.11 0.00
56630.11 197072.80
0.00 −56630.11
394145.59 ⎦ ⎥
⎥ ⎥
⎥ ⎤
Element d :
[ �
�
] = ⎣
⎢ ⎢
⎢ ⎢
⎡ 130608.72
0.00 0.00
−130608.72 0.00
0.00 0.00
10848.68 56630.11
0.00 −10848.68
56630.11 0.00
56630.11 394145.59
0.00 −56630.11
197072.80 −130608.72
0.00 0.00
130608.72 0.00
0.00 0.00
−10848.68 −56630.11
0.00 10848.68
−56630.11 0.00
56630.11 197072.80
0.00 −56630.11
394145.59 ⎦ ⎥
⎥ ⎥
⎥ ⎤
Universitas Sumatera Utara
Element e :
[ �
�
] = ⎣
⎢ ⎢
⎢ ⎢
⎡ 53047.29
0.00 0.00
−53047.29 0.00
0.00 0.00
1064.39 11112.28
0.00 −1064.39
11112.28 0.00
11112.28 154682.95
0.00 −11112.28
77341.48 −53047.29
0.00 0.00
53047.29 0.00
0.00 0.00
−1064.39 −11112.28
0.00 1064.39
−11112.28 0.00
11112.28 77341.48
0.00 −11112.28
154682.95 ⎦
⎥ ⎥
⎥ ⎥
⎤
Element f :
��
�
� = ⎣
⎢ ⎢
⎢ ⎢
⎡ 106094.59
0.00 0.00
−106094.59 0.00
0.00 0.00
8515.16 44449.12
0.00 −8515.16
44449.12 0.00
44449.12 309365.90
0.00 −44449.12
154682.95 −106094.59
0.00 0.00
106094.59 0.00
0.00 0.00
−8515.16 −44449.12
0.00 8515.16
−44449.12 0.00
44449.12 154682.95
0.00 −44449.12
309365.90 ⎦
⎥ ⎥
⎥ ⎥
⎤
Element g :
��
�
� = ⎣
⎢ ⎢
⎢ ⎢
⎡ 42142.94
0.00 0.00
−42142.94 0.00
0.00 0.00
1162.51 9881.31
0.00 −1162.51
9881.31 0.00
9881.31 111988.24
0.00 −9881.31
55994.12 −42142.94
0.00 0.00
42142.94 0.00
0.00 0.00
−1162.51 −9881.31
0.00 1162.51
−9881.31 0.00
9881.31 55994.12
0.00 −9881.31
111988.24⎦ ⎥
⎥ ⎥
⎥ ⎤
• Langkah III : menentukan matriks kekakuan global element
���� = [�][�][�]
−1
���
�
� = �
�
⎣ ⎢
⎢ ⎢
⎢ ⎢
⎢ ⎢
⎢ ⎢
⎢ ⎢
⎡ ��
2
+ 12
� �
2
�
2
�� − 12
� �
2
� �� − 6
� �
� �� −
12 �
�
2
� �� ��
2
+ 12
� �
2
�
2
6 �
� �
− 6
� �
� 6
� �
� 4
� − ���
2
+ 12
� �
2
�
2
� − �� −
12 �
�
2
� �� −
6 �
� �
− �� − 12
� �
2
� �� − ���
2
+ 12
� �
2
�
2
� 6
� �
� 6
� �
� −
6 �
� �
2 �
− ���
2
+ 12
� �
2
�
2
� − �� −
12 �
�
2
� �� 6
� �
� − �� −
12 �
�
2
� �� − ���
2
+ 12
� �
2
�
2
� − 6
� �
� −
6 �
� �
6 �
� �
2 �
��
2
+ 12
� �
2
�
2
�� − 12
� �
2
� �� − 6
� �
� �� −
12 �
�
2
� �� ��
2
+ 12
� �
2
�
2
− 6
� �
� −
6 �
� �
− 6
� �
� 4
� ⎦ ⎥
⎥ ⎥
⎥ ⎥
⎥ ⎥
⎥ ⎥
⎥ ⎥
⎤
Element a :
[ �
�
] = ⎣
⎢ ⎢
⎢ ⎢
⎡ 7214.400
0.000 −36072
−7214.400 0.000
−36072 0.000
85337.000 0.000
0.000 −85337.000
0.000 −36072
0.000 24048
36072 0.000
120240 −7214.400
0.000 36072
7214.400 0.000
−36072 0.000
−85337.000 0.000
0.000 85337.000
0.000 −36072
0.000 120240
−36072 0.000
24048 ⎦ ⎥
⎥ ⎥
⎥ ⎤
Universitas Sumatera Utara
Element b :
[ �
�
] = ⎣
⎢ ⎢
⎢ ⎢
⎡ 7214.400
0.000 −36072
−7214.400 0.000
−36072 0.000
85337.000 0.000
0.000 −85337.000
0.000 −36072
0.000 240480
36072 0.000
120240 −7214.400
0.000 36072
7214.400 0.000
−36072 0.000
−85337.000 0.000
0.000 85337.000
0.000 −36072
0.000 120240
−36072 0.000
240480 ⎦ ⎥
⎥ ⎥
⎥ ⎤
Element c :
[ �
�
] = ⎣
⎢ ⎢
⎢ ⎢
⎡ 120730.907
120730.907 −16263.792
−120730.907 −32945.344
−16263.792 32945.344
20726.491 54244.437
−32945.344 −20726.491
54244.437 −16263.792
54244.437 394145.594
16263.7918 −54244.437
197072.797 −120730.907
−32945.344 16263.7918
120730.907 32945.344
−16263.792 −32945.344
−20726.491 −54244.437
32945.344 20726.491
−54244.437 −16263.792
54244.437 197072.8
−16263.792 −54244.437
394145.59 ⎦
⎥ ⎥
⎥ ⎥
⎤
Element c :
[ �
�
] = ⎣
⎢ ⎢
⎢ ⎢
⎡ 120730.907
32945.344 −16263.792
−120730.907 −32945.34
−16263.792 32945.344
20726.491 54244.437
−32945.344 −20726.491
54244.437 −16263.792
54244.437 394145.594
16263.7918 −54244.437
197072.797 −120730.907
−32945.344 16263.7918
120730.907 32945.344
−16263.792 −32945.344
−20726.491 −54244.437
32945.344 20726.491
−54244.437 −16263.792
54244.437 197072.8
16263.792 −16263.792
394145.59 ⎦
⎥ ⎥
⎥ ⎥
⎤
Element d :
[ �
�
] = ⎣
⎢ ⎢
⎢ ⎢
⎡ 120730.907
32945.344 −16263.79
−120730.907 −32945.344
−16263.792 32945.344
20726.491 54244.437
−32945.344 −20726.491
54244.437 −16263.792
54244.437 394145.594
16263.7918 −54244.437
197072.797 −120730.907
−32945.344 16263.7918
120730.907 32945.344
−16263.792 −32945.344
−20726.491 −54244.437
32945.344 20726.491
−54244.437 −16263.792
54244.437 197072.8
−16263.792 −54244.437
394145.59 ⎦
⎥ ⎥
⎥ ⎥
⎤
Element e :
[ �
�
] = ⎣
⎢ ⎢
⎢ ⎢
⎡ 98046.235
−26843.579 12765.4924
−98046.235 26843.579
12765.4924 −26843.579
16563.511 42576.599
26843.579 −16563.511
42576.599 12765.4924
42576.599 309365.9
−12765.492 −42576.599
154682.95 −98046.235
26843.579 −12765.492
98046.235 −26843.579
12765.4924 26843.579
−16563.511 −42576.599
−26843.579 16563.511
−42576.599 12765.492
42576.599 154682.95
12765.492 −42576.59
309365.9 ⎦ ⎥
⎥ ⎥
⎥ ⎤
Element f:
��
�
� = ⎣
⎢ ⎢
⎢ ⎢
⎡ 98046.235
−26843.579 12765.4924
−98046.235 26843.579
12765.4924 −26843.579
16563.511 42576.599
26843.579 −16563.511
42576.599 12765.4924
42576.599 309365.9
−12765.492 −42576.599
154682.95 −98046.235
26843.579 −12765.492
98046.235 −26843.579
12765.4924 26843.579
−16563.511 −42576.599
−26843.579 16563.511
−42576.599 12765.492
42576.599 154682.95
12765.492 −42576.599
309365.9 ⎦ ⎥
⎥ ⎥
⎥ ⎤
Universitas Sumatera Utara
Element g:
��
�
� = ⎣
⎢ ⎢
⎢ ⎢
⎡ 1162.508
0.000 9881.31488
−1162.508 0.000
9881.31488 0.000
42142.941 0.000
0.000 −42142.941
0.000 9881.31488
0.000 111988.235
−9881.3149 0.000
55994.1176 −1162.508
0.000 −9881.3149
1162.508 0.000
9881.31488 0.000
−42142.941 0.000
0.000 42142.941
0.000 9881.3149
0.000 55994.118
9881.3149 0.000
111988.24 ⎦
⎥ ⎥
⎥ ⎥
⎤
• Langkah IV : Menentukan matriks kekakuan struktur
��̅
1
� = ���
�
11
���̅
1
� + ���
�
12
���̅
2
�
��̅
2
� = ���
�
21
���̅
1
� + ���
�
22
���̅
2
� + ���
�
22
���̅
2
� + ���
�
23
���̅
3
�
��̅
3
� = ���
�
32
���̅
2
� + ���
�
33
���̅
3
� + ���
�
33
���̅
3
� + ���
�
34
���̅
4
�
��̅
4
� = ���
�
43
���̅
3
� + ���
�
44
���̅
4
� + ���
�
44
���̅
4
� + ���
�
45
���̅
5
�
��̅
5
� = ���
�
54
���̅
4
� + ���
�
55
���̅
5
� + ���
�
55
���̅
5
� + ���
�
56
���̅
6
�
��̅
6
� = ���
�
65
���̅
5
� + ���
�
66
���̅
6
� + ���
�
66
���̅
6
� + ���
�
67
���̅
7
�
��̅
7
� = ���
�
76
���̅
6
� + ���
�
77
���̅
7
� + ���
�
77
���̅
7
� + ���
�
78
���̅
8
�
��̅
8
� = ���
�
87
���̅
7
� + ���
�
88
���̅
8
�
⎩ ⎪
⎪ ⎪
⎨ ⎪
⎪ ⎪
⎧� ̅
1
�̅
2
�̅
3
�̅
4
�̅
5
�̅
6
�̅
7
�̅
8
⎭ ⎪
⎪ ⎪
⎬ ⎪
⎪ ⎪
⎫
= ⎣
⎢ ⎢
⎢ ⎢
⎢ ⎢
⎡��
�11
��
�21
��
�12
��
�22
+ ��
�22
��
�32
��
�23
��
�33
+ ��
�33
��
�43
��
�34
��
�44
+ ��
�44
��
�54
��
�45
��
�55
+ ��
�55
��
�65
��
�56
��
�66
+ ��
�66
��
�76
��
�67
��
�77
+ ��
�77
��
�87
��
�78
��
�88
⎦ ⎥
⎥ ⎥
⎥ ⎥
⎥ ⎤
⎩ ⎪
⎪ ⎪
⎨ ⎪
⎪ ⎪
⎧� ̅
1
�̅
2
�̅
3
�̅
4
�̅
5
�̅
6
�̅
7
�̅
8
⎭ ⎪
⎪ ⎪
⎬ ⎪
⎪ ⎪
⎫
• Langkah V : Menentukan kondisi-kondisi batas Boundary condition
Dengan meninjau kondisi batas pada kedua simpul 1 dan 8 merupakan jepit sehingga pada kedua simpul ini tidak akan terjadi perpindahan sehingga :
• �̅
1
= 0 • �̅
8
= 0
Universitas Sumatera Utara
⎩ ⎪
⎪ ⎨
⎪ ⎪
⎧� ̅
2
�̅
3
�̅
4
�̅
5
�̅
6
�̅
7
⎭ ⎪
⎪ ⎬
⎪ ⎪
⎫ =
⎣ ⎢
⎢ ⎢
⎢ ⎢
⎡��
�22
+ ��
�22
��
�32
��
�23
��
�33
+ ��
�33
��
�43
��
�34
��
�44
+ ��
�44
��
�54
��
�45
��
�55
+ ��
�55
��
�65
��
�56
��
�66
+ ��
�66
��
�76
��
�67
��
�77
+ ��
�77
⎦ ⎥
⎥ ⎥
⎥ ⎥
⎤
⎩ ⎪
⎪ ⎨
⎪ ⎪
⎧� ̅
2
�̅
3
�̅
4
�̅
5
�̅
6
�̅
7
⎭ ⎪
⎪ ⎬
⎪ ⎪
⎫
⎩ ⎪
⎪ ⎪
⎪ ⎪
⎪ ⎨
⎪ ⎪
⎪ ⎪
⎪ ⎪
⎧ 1
−4
−3 0 ⎭
⎪ ⎪
⎪ ⎪
⎪ ⎪
⎬ ⎪
⎪ ⎪
⎪ ⎪
⎪ ⎫
=
⎣ ⎢
⎢ ⎢
⎢ ⎢
⎢ ⎢
⎢ ⎢
⎢ ⎢
⎢ ⎢
⎢ ⎡
14428.80 −72144.00
−7214.40 −36072.00
170674.00 −85337.00
−72144.00 480960.00
36072.00 120240.00
−7214.40 36072.00
127945.31 32945.34
−52335.79 −120730.91
−32945.34 −16263.79
−85337.00 32945.34
106063.49 54244.44
−32945.34 −20726.49
54244.44 −36072.00
120240.00 −52335.79
54244.44 634625.59
16263.79 −54244.44
197072.80 − 120730.91
−32945.34 16263.79
241461.81 65890.69
−32527.58 −120730.91
−32945.34 −16263.79
−32945.34 −20726.49
−54244.44 65890.69
41452.98 −32945.34
−20726.49 54244.44
−16263.79 54244.44
197072.80 −32527.58
788291.19 16263.79
−54244.44 197072.80
−120730.91 −32945.34
16263.79 169490.65
18645.13 −13072.42
−48759.74 14300.22
3191.37 −32945.34
−20726.49 −54244.44
18645.13 26078.44
−43600.29 14300.22
−5351.95 10644.15
−16263.79 54244.44
197072.80 −13072.42
−43600.29 548828.54
−3191.37 −10644.15
77341.48 −48759.74
14300.22 −3191.37
146805.98 −41143.80
15956.87 −98046.24
26843.58 12765.49
14300.22 −5351.95
−10644.15 −41143.80
21915.46 31932.45
26843.58 −16563.51
42576.60 3191.37
10644.15 77341.48
15956.87 31932.45
464048.85 −12765.49
−42576.60 154682.95
−98046.24 26843.58
−12765.49 99208.74
−26843.58 22646.81
26843.58 −16563.51
−42576.60 −26843.58
58706.45 −42576.60
12765.49 42576.60
154682.95 22646.81
−42576.60 421354.14
⎦ ⎥
⎥ ⎥
⎥ ⎥
⎥ ⎥
⎥ ⎥
⎥ ⎥
⎥ ⎥
⎥ ⎤
⎩ ⎪
⎪ ⎪
⎪ ⎪
⎪ ⎪
⎨ ⎪
⎪ ⎪
⎪ ⎪
⎪ ⎪
⎧ ��
2
�̅
2
�̅
2
��
3
�̅
3
�̅
3
��
4
�̅
4
�̅
4
��
5
�̅
5
�̅
5
��
6
�̅
6
�̅
6
��
7
�̅
7
�̅
7
⎭ ⎪
⎪ ⎪
⎪ ⎪
⎪ ⎪
⎬ ⎪
⎪ ⎪
⎪ ⎪
⎪ ⎪
⎫
• Langkah VI : Menghitung besar perpindahan
Setelah memasukkan nilai-nilai syarat-syarat batas maka, Penyelesaian matriks di atas menghasilkan
o ��
2
= 3.69139 x 10
-4
m o
��
5
= 3.74576x 10
-5
m o
�̅
2
= -1.27499 x 10
-5
m o
�̅
5
=-7.43508x 10
-5
m o
�̅
2
= 4.86912 x 10
-5
rad o
�̅
5
= 6.00802x 10
-6
rad o
��
3
= -4.16775x 10
-5
m o
��
6
= 3.48351x 10
-5
m o
�̅
3
=-2.54998x 10
-5
m o
�̅
6
= 2.66999 x 10
-4
m o
�̅
3
=-1.42155x 10
-5
rad o
�̅
6
= 1.45380x 10
-5
rad
Universitas Sumatera Utara
o ��
4
= 3.151116x 10
-5
m o
��
7
= 2.95123x 10
-5
m o
�̅
4
=-4.05023x 10
-5
m o
�̅
7
=-2.16397x 10
-5
m o
�̅
4
=-3.87754x 10
-6
rad o
�̅
7
=-1.89250x 10
-5
rad
• Langkah VII : Menentukan perpindahan lokal
{ �} = [�]
−1
��̅� Element a :
⎩ ⎪
⎨ ⎪
⎧ �
1
�
1
�
1
�
2
�
2
�
2
⎭ ⎪
⎬ ⎪
⎫ =
⎣ ⎢
⎢ ⎢
⎡ −1
1 1
−1 1
1⎦ ⎥
⎥ ⎥
⎤ ⎩
⎪ ⎨
⎪ ⎧
3.69139 x 10
−4
−127499 x 10
−5
4.86912 x 10
−5
⎭ ⎪
⎬ ⎪
⎫ =
⎩ ⎪
⎨ ⎪
⎧ −1.27499 x 10
−5
−369139 x 10
−4
4.86912 x 10
−5
⎭ ⎪
⎬ ⎪
⎫
Element b :
⎩ ⎪
⎨ ⎪
⎧ �
2
�
2
�
2
�
3
�
3
�
3
⎭ ⎪
⎬ ⎪
⎫ =
⎣ ⎢
⎢ ⎢
⎡ −1
1 1
−1 1
1⎦ ⎥
⎥ ⎥
⎤
⎩ ⎪
⎨ ⎪
⎧ 3.69139 x 10
−4
−1.27499 x 10
−5
4.86912 x 10
−5
4.16775 x 10
−5
−1.08452 x 10
−4
−4.10282 x 10
−5
⎭ ⎪
⎬ ⎪
⎫ =
⎩ ⎪
⎨ ⎪
⎧− 5.42259 x 10
−5
−2.58694 x 10
−4
2.10694 x 10
−5
−1.08452 x 10
−4
−3.73223 x 10
−4
−4.10282 x 10
−5
⎭ ⎪
⎬ ⎪
⎫
Element c :
⎩ ⎪
⎨ ⎪
⎧ �
3
�
3
�
3
�
4
�
4
�
4
⎭ ⎪
⎬ ⎪
⎫ =
⎣ ⎢
⎢ ⎢
⎡ 0.958
−0.287 0.287
0.958 1
0.958 −0.287
0.287 0.958
1⎦ ⎥
⎥ ⎥
⎤ ⎩
⎪ ⎨
⎪ ⎧
3.73223 x 10
−4
−1.08452 x 10
−4
−4.10282 x 10
−5
6.85091 x 10
−4
−1.10575 x 10
−3
−6.53135 x 10
−5
⎭ ⎪
⎬ ⎪
⎫ =
⎩ ⎪
⎨ ⎪
⎧ 3.26353 x 10
−4
−2.11070 x 10
−4
−4.10282 x 10
−5
3.38665 x 10
−4
−1.25592 x 10
−3
−6.53135 x 10
−5
⎭ ⎪
⎬ ⎪
⎫
Element d :
⎩ ⎪
⎨ ⎪
⎧ �
4
�
4
�
4
�
5
�
5
�
5
⎭ ⎪
⎬ ⎪
⎫ =
⎣ ⎢
⎢ ⎢
⎢ ⎡
0.958 −0.287
0.287 0.958
1 0.958
−0.287 0.287
0.958 1
⎦ ⎥
⎥ ⎥
⎥ ⎤
⎩ ⎪
⎨ ⎪
⎧ 6.85091 x 10
−4
−1.10575 x 10
−3
−6.53135 x 10
−5
7.58800 x 10
−4
−1.22384 x 10
−3
7.65260 x 10
−5
⎭ ⎪
⎬ ⎪
⎫ =
⎩ ⎪
⎨ ⎪
⎧ 3.38665 x 10
−4
−1.25592 x 10
−3
−6.53135 x 10
−5
3.75354 x 10
−4
−1.39021 x 10
−3
7.65260 x 10
−5
⎭ ⎪
⎬ ⎪
⎫
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Element e :
⎩ ⎪
⎨ ⎪
⎧ �
5
�
5
�
5
�
6
�
6
�
6
⎭ ⎪
⎬ ⎪
⎫ =
⎣ ⎢
⎢ ⎢
⎢ ⎡
0.958 0.287
−0.287 0.958
1 0.958
0.287 −0.287
0.958 1
⎦ ⎥
⎥ ⎥
⎥ ⎤
⎩ ⎪
⎨ ⎪
⎧ 7.58800 x 10
−4
−1.22384 x 10
−3
7.65260 x 10
−5
1.18990 x 10
−3
3.22993 x 10
−5
3.48524 x 10
−5
⎭ ⎪
⎬ ⎪
⎫ =
⎩ ⎪
⎨ ⎪
⎧ 1.07831 x 10
−3
−9.54364 x 10
−4
7.65260 x 10
−5
1.13049 x 10
−3
3.72669 x 10
−4
3.48524 x 10
−5
⎭ ⎪
⎬ ⎪
⎫
Element f :
⎩ ⎪
⎨ ⎪
⎧ �
6
�
6
�
6
�
7
�
7
�
7
⎭ ⎪
⎬ ⎪
⎫ =
⎣ ⎢
⎢ ⎢
⎢ ⎡
0.958 0.287
−0.287 0.958
1 0.958
0.287 −0.287
0.958 1
⎦ ⎥
⎥ ⎥
⎥ ⎤
⎩ ⎪
⎨ ⎪
⎧ 1.18990 x 10
−3
3.22993 x 10
−5
3.48524 x 10
−5
1.18419 x 10
−3
−5.62971 x 10
−5
−1.21444 x 10
−4
⎭ ⎪
⎬ ⎪
⎫ =
⎩ ⎪
⎨ ⎪
⎧ 1.13049 x 10
−3
3.72669 x 10
−4
3.48524 x 10
−5
1.15047 x 10
−3
2.86165 x 10
−4
−1.21444 x 10
−4
⎭ ⎪
⎬ ⎪
⎫
Element g :
⎩ ⎪
⎨ ⎪
⎧ �
7
�
7
�
7
�
8
�
8
�
8
⎭ ⎪
⎬ ⎪
⎫ =
⎣ ⎢
⎢ ⎢
⎢ ⎡
1 −1
1 1
−1 1⎦
⎥ ⎥
⎥ ⎥
⎤
⎩ ⎪
⎨ ⎪
⎧ 1.18419 x 10
−3
−5.62971 x 10
−5
−1.21444 x 10
−4
⎭ ⎪
⎬ ⎪
⎫ =
⎩ ⎪
⎨ ⎪
⎧ 5.62971 x 10
−5
1.18419 x 10
−3
−1.21444 x 10
−4
⎭ ⎪
⎬ ⎪
⎫
• Langkah VIII : Menentukan gaya-gaya dalam lokal masing-masing
element
{ �} = [�]{�}
Universitas Sumatera Utara
hasil perhitungan gaya –gaya dalam masing –masing element dapat dilihat pada tabel berikut ini:
tabel 4.1 Gaya –gaya dalam masing –masing element
Element Ujung batang
Gaya Normal Ton
Gaya lintang Ton
Momen Tonm
A 1
1.09 4.42
7.51 2
-109 -4.42
0.56 B
2 1.09
-0.09 -0.56
3 -1.09
0.09 18.69
C 3
1.38 0.72
-18.69 4
-1.38 -0.72
-12.95 D
4 0.98
-0.98 12.95
5 -0.98
0.20 -4.59
E 5
0.74 0.31
4.59 6
-0.74 -0.31
-9.61 F
6 0.94
-0.67 9.61
7 -0.94
0.67 17.88
G 7
0.91 0.22
-17.88 8
-0.91 -0.22
-12.94
4.2 gambar bidang momen
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4.3. Memodifikasi kekakuan batang akibat terbentuknya sendi plastis