INSTABILITY AT JOINT ## DIRECTION = MY, MX

Hi.

I'm currently working on a 24m-weighbridge platform.

However, the  initial output resulted to several instabilities.

I have eliminate the instabilities but could someone guide/enlighten me how should I avoid or correct this?

Thanks in advance.

Here it is:

STAAD SPACE

START JOB INFORMATION

ENGINEER DATE 22-Mar-17

ENGINEER NAME X

END JOB INFORMATION

UNIT METER KN

JOINT COORDINATES

1 0.245 1.925 0.2; 2 1.445 1.925 0.2; 3 0.245 1.925 6; 4 1.445 1.925 6;

5 0 1.925 12; 6 1.445 1.925 12; 7 0 1.925 17.6; 8 1.445 1.925 17.6;

10 0.245 1.925 24; 11 1.745 1.925 24; 12 0.245 2.725 21.5;

13 1.745 2.725 21.5; 14 0.245 2.725 23.1; 15 1.745 2.725 23.1;

16 0.245 3.325 18.7; 17 1.745 3.325 18.7; 18 0.245 3.325 20.4;

19 1.745 3.325 20.4; 20 0 3.76 17.6; 21 0.245 3.76 17.6;

22 1.445 3.76 17.6; 23 1.745 3.76 17.6; 24 0.245 3.925 15.95;

25 1.745 3.925 15.95; 26 0.245 3.925 17.6; 27 1.445 3.925 17.6;

28 1.745 3.925 17.6; 29 0.245 4.525 13.2; 30 1.745 4.525 13.2;

31 0.245 4.525 14.85; 32 1.745 4.525 14.85; 33 0.245 4.96 0.2;

34 1.445 4.96 0.2; 35 1.745 4.96 0.2; 36 0.245 4.96 6; 37 1.445 4.96 6;

38 1.745 4.96 6; 39 0 4.96 12; 40 0.245 4.96 12; 41 1.445 4.96 12;

42 1.745 4.96 12; 43 0.245 5.125 0; 44 1.745 5.125 0;

45 0.245 5.125 0.2; 46 1.745 5.125 0.2; 47 0.245 5.125 2;

48 1.745 5.125 2; 49 0.245 5.125 4; 50 1.745 5.125 4; 51 0.245 5.125 6;

52 1.445 5.125 6; 53 1.745 5.125 6; 54 0.245 5.125 8; 55 1.745 5.125 8;

56 0.245 5.125 10; 57 1.745 5.125 10; 58 0.245 5.125 12;

59 1.445 5.125 12; 60 1.745 5.125 12; 61 0.245 5.125 12.35;

62 1.745 5.125 12.35; 64 0.245 3.375 0.2; 65 1.445 3.375 0.2;

66 0.245 3.375 6; 67 1.445 3.375 6; 68 0 3.375 12; 69 1.445 3.375 12;

MEMBER INCIDENCES

1 14 10; 2 15 11; 3 12 13; 4 12 14; 5 13 15; 6 14 15; 7 7 20; 8 8 22;

9 18 12; 10 19 13; 11 16 17; 12 16 18; 13 17 19; 14 18 19; 15 1 64;

16 2 65; 17 3 66; 18 4 67; 19 5 68; 20 6 69; 22 26 16; 23 28 17;

24 20 21; 25 21 22; 26 22 23; 27 24 25; 28 24 26; 29 25 28; 30 26 27;

31 27 28; 32 31 24; 33 32 25; 34 29 30; 35 29 31; 36 30 32; 37 31 32;

38 61 29; 39 62 30; 40 33 34; 41 34 35; 42 36 37; 43 37 38; 44 39 40;

45 40 41; 46 41 42; 47 43 44; 48 43 45; 49 44 46; 50 45 47; 51 46 48;

52 47 48; 53 47 49; 54 48 50; 55 49 50; 56 49 51; 57 50 53; 58 51 52;

59 52 53; 60 51 54; 61 53 55; 62 54 55; 63 54 56; 64 55 57; 65 56 57;

66 56 58; 67 57 60; 68 58 59; 69 59 60; 70 58 61; 71 60 62; 72 64 33;

73 65 34; 74 64 65; 75 66 36; 76 67 37; 77 66 67; 78 68 39; 79 69 41;

80 68 69; 81 1 65; 82 64 34; 83 3 67; 84 66 37; 85 5 69; 86 68 41;

87 7 22; 88 43 48; 89 48 49; 90 49 53; 91 53 54; 92 54 57; 93 57 58;

94 29 32; 95 25 26; 96 16 19; 97 13 14;

DEFINE MATERIAL START

ISOTROPIC STEEL

E 2.05e+008

POISSON 0.3

DENSITY 76.8195

ALPHA 1.2e-005

DAMP 0.03

TYPE STEEL

STRENGTH FY 253200 FU 407800 RY 1.5 RT 1.2

END DEFINE MATERIAL

MEMBER PROPERTY EUROPEAN

88 TO 97 TABLE ST L60X60X6

MEMBER PROPERTY COLDFORMED EUROPEAN

74 77 80 TO 87 TABLE ST CHS48.3X3

MEMBER PROPERTY EUROPEAN

1 2 4 5 9 10 12 13 22 23 28 29 32 33 35 36 38 39 47 TO 51 53 54 56 -

57 60 61 63 64 66 67 70 71 TABLE ST UPN240

3 6 11 14 27 30 31 34 37 52 55 58 59 62 65 68 69 TABLE ST IPE100

8 15 TO 18 20 24 TO 26 40 TO 46 72 73 75 76 79 TABLE ST HE100A

7 19 78 TABLE ST 150X5SHS

CONSTANTS

BETA 180 MEMB 2 5 10 13 23 29 33 36 39 47 49 51 54 57 61 64 67 71

MATERIAL STEEL ALL

SUPPORTS

1 TO 8 10 11 PINNED

MEMBER RELEASE

8 73 76 79 END MY MZ

MEMBER TRUSS

81 TO 97

SLAVE FY MASTER 33 JOINT 45

SLAVE FY MASTER 35 JOINT 46

SLAVE FY MASTER 36 JOINT 51

SLAVE FY MASTER 38 JOINT 53

SLAVE FY MASTER 40 JOINT 58

SLAVE FY MASTER 42 JOINT 60

SLAVE FY MASTER 21 JOINT 26

SLAVE FY MASTER 23 JOINT 28

LOAD 1 LOADTYPE Dead TITLE DEAD LOAD SELFWEIGHT (GS)

SELFWEIGHT Y -1

LOAD 2 LOADTYPE Dead TITLE DEAD LOAD GRATING, KICK PLATES (GO)

MEMBER LOAD

1 2 4 5 9 10 12 13 22 23 28 29 32 33 35 36 38 39 48 TO 51 53 54 56 -

57 60 61 63 64 66 67 70 71 UNI GY -0.75

LOAD COMB 1001 1.35(GS+GO)

1 1.35 2 1.35

LOAD COMB 1002 1.35(GS+GO) + 1.5Q

1 1.35 2 1.35

PERFORM ANALYSIS

DEFINE ENVELOPE

1001 1002 ENVELOPE 1000 TYPE STRENGTH

END DEFINE ENVELOPE

PERFORM ANALYSIS

LOAD LIST ENV 1000

PARAMETER 1

CODE EN 1993-1-1:2005

NA 1 MEMB 1 TO 20 22 TO 39 41 43 47 TO 68 70 TO 73 75 76 78 79

SGR 2 MEMB 1 TO 20 22 TO 73 75 76 78 79

SGR 0 MEMB 74 77 80 TO 97

TRACK 0 ALL

CHECK CODE ALL

FINISH