I'm running a test STAAD model to practice performing a dynamic analysis of a 3 story concrete framed structure with concrete shear walls. The 1st and 2nd stories are modeled as rigid diaphragms while the roof is modeled as a flexible diaphragm. I've applied the dead loads as well as the dynamic masses as reference loads. When I run the model, I get a base shear of 514.79 kips using the ELF procedure but my dynamic base shear is only 263 kips. That's only ~50% of my static base shear (much less than the minimum 85% required per ASCE 7-10). Is this a common error with STAAD? My dead loads and dynamic masses are identical so I don't see how I can get that much of a difference in base shear. Is there something I'm doing wrong or is this common and I need to go in and scale my forces per ASCE 7-10 section 12.9.4.1 (basically 0.85*static base shear divided by dynamic base shear).

Here's a summary of my reference load cases:

DEFINE REFERENCE LOADS
LOAD R1 LOADTYPE Dead TITLE DEAD LOAD
SELFWEIGHT Y -1
FLOOR LOAD
_1ST_FLOOR FLOAD -0.1 GY
_2ND_FLOOR FLOAD -0.1 GY
_ROOF FLOAD -0.05 GY
LOAD R2 LOADTYPE Mass TITLE DYNAMIC MASS
SELFWEIGHT X 1
SELFWEIGHT Y 1
SELFWEIGHT Z 1
FLOOR LOAD
_1ST_FLOOR FLOAD 0.1 GX
_1ST_FLOOR FLOAD 0.1 GY
_1ST_FLOOR FLOAD 0.1 GZ
_2ND_FLOOR FLOAD 0.1 GX
_2ND_FLOOR FLOAD 0.1 GY
_2ND_FLOOR FLOAD 0.1 GZ
_ROOF FLOAD 0.05 GX
_ROOF FLOAD 0.05 GY
_ROOF FLOAD 0.05 GZ
END DEFINE REFERENCE LOADS

Copy of my model:

communities.bentley.com/.../Dynamic-Analysis-test-part-2.STD

When performing a modal analysis you need to add factors for the seismic load (essentially I/R per ASCE 7) as well as factors for Dynamic Eccentricity (DEC) and Accidental Eccentricity (ECC). My understanding is that DEC is inherent torsion. For an analysis in the positive X direction with positive eccentricity the factors for the seismic load and DEC are both positive (with DEC being 1) and the factor for ECC is positive as well (0.05). For eccentricity in the negative direction the sign for ECC would be negative (-0.05). Is it true that when considering a seismic load in the negative X direction the factors for both the seismic load and DEC are negative? Thanks.

Hi all,

I will be thankful if you can answer my question and give guidance in this regard.

we are designing a raft foundation using staad pro SS6.

we are assuming 

1. We are designing this foundation for 25 mm settlement and bearing capacity is 200kN/m2.

2. We are using IS 456:2000 code for this concrete design.

3.Modulus of subgrade reaction as (200kn/m2)/0.025=10000Kn/m2/m.

4. we are considering elastic mat support direct y only subgrade 10000kn/m3 for all node points.

5. Now for the points below the column, we are taking support reactions are (10000*influence area of that column )=(10000*0.4*0.4*4)=6400Kn/m2/m and on those points supports specifications we are providing as 

"FIXED BUT MX MZ KFY 6400 "to transfer this column load to the foundation.

5. We are eliminating that portion (influence area below the column)in case of design.

my questions are

1 Is it okay if we providing this supports specifications below the column influence area points?

2. For which value of settlement we shall consider this, if modules of subgrade reaction test  is not performed on site.

should we consider immediate settlement value or just take 25mm settlement value?

3. While generating the plate stress contour we have seen that below the column influence are zone we don't get any stress value is it okay or not?

Staad.Pro is not possible to check with recently ASD code?

Do we have to still use ASD1994 only?

Hi 

I went through the thread "How to design a non standard cold formed section in STAAD.Pro" and carried out an analysis by adding my npn-standard section in the section database. But the software showed the error "**ERROR- IN READING MEMBER PROPERTIES. CHECK DATA FORMAT CAREFULLY." Please let me know how to solve this error.

1. Please explain below warning:

WARNING: For member#    306 the profile has been selected from HSS Rect/Round (non A1085)/Pipe
            tables of AISC database. Weld type is considered to be Elect-resist-weld.
            Thickness is already reduced from the table. Further reductions will not be done.

2. We have considered serviceability and strength checks based on AISC 2010 ASD in two separate envelopes. Parameter 1 and Parameter 2 are created for separate strength and serviceability checks accordingly. While output file shows UR for each parameter (1 & 2), in the graphics window we see that the UR for the last parameter defined (in our case being serviceability) overrides the result from previously defined parameter. This is not useful, as in some instances a higher strength UR is overridden by a lower serviceability UR. Please advise on how we can get graphics window showing both results separately.

Thanks

communities.bentley.com/.../GM-OFFICE-BUILDING.pdf

I have a rectangular column with 8 bars, tied as such:

When looking at the results, the 6 six shear bars in the major direction are utilized, but the 2 in the minor are not used - can you explain this?

Even if I increase the number of minor direction shear legs, Vs remains 0 in the minor direction:

Am I missing something? I have looked in the manual, but find no information pertaining to this.

I'm working with a larger STAAD model that was generated from a 3D model software. There are a lot of problems with beams being not being connected or aligned. I started to write a macro that would allow me to move a node to closest point on a selected beam but I'm having problems with the SetNodeCoordinate command. The SetNodeCoordinate runs but nothing seems to happen. I am able to create a new node in the desired location with the AddNode command but moving a node would be much better.

Here's a minimal code and STAAD file that I'm testing on.

Sub Test()

Dim OS As Object
Set OS = GetObject(, "StaadPro.OpenSTAAD")

OS.Geometry.SetNodeCoordinate 3, 30, 0, 0

End Sub

Alternatively, if there's a command to change the beam incidence that would also work but currently I'm doing that part manually.

Thank you.

communities.bentley.com/.../Test-Node-Coordinate.STD

Good Morning

In the analisys show this error message: Member "1204" does not have valid geometry.

This member don't show in the model but show conected in "one node". I can't deleted the node.  

Thanks

Hello,

I am getting instabilities in all of the nodes in my plate mesh. I am newer to STAAD and would like some assistance understanding what I am doing wrong.

communities.bentley.com/.../Bin.STD

Hello,

I have done several steel design in STAAD PRO and this time I moved on to do concrete design using plates. I got shear and moments from the model but how do I say what's the moment at top of concrete and what's at the bottom?

Is there a way to differentiate between them?

Also when I was doing concrete design in STAAD, it shows me only minimum steel required. Is this the right way to design reinforcements in STAAD?

Thanks

STAAD SPACE
START JOB INFORMATION
ENGINEER DATE 09-Apr-19
END JOB INFORMATION
INPUT WIDTH 79
UNIT FEET KIP
JOINT COORDINATES
1 0 2 8; 3 16.1 2 8; 4 0 0 0; 5 0 0 1; 6 1 0 0; 7 1 0 1; 8 2 0 0; 9 2 0 1;
10 3 0 0; 11 3 0 1; 12 4 0 0; 13 4 0 1; 14 5 0 0; 15 5 0 1; 16 6 0 0; 17 6 0 1;
18 7 0 0; 19 7 0 1; 20 8 0 0; 21 8 0 1; 22 9 0 0; 23 9 0 1; 24 10 0 0;
25 10 0 1; 26 11 0 0; 27 11 0 1; 28 12 0 0; 29 12 0 1; 30 13 0 0; 31 13 0 1;
32 14 0 0; 33 14 0 1; 34 15 0 0; 35 15 0 1; 36 16 0 0; 37 16 0 1; 38 0 0 2;
39 1 0 2; 40 2 0 2; 41 3 0 2; 42 4 0 2; 43 5 0 2; 44 6 0 2; 45 7 0 2; 46 8 0 2;
47 9 0 2; 48 10 0 2; 49 11 0 2; 50 12 0 2; 51 13 0 2; 52 14 0 2; 53 15 0 2;
54 16 0 2; 55 0 0 3; 56 1 0 3; 57 2 0 3; 58 3 0 3; 59 4 0 3; 60 5 0 3;
61 6 0 3; 62 7 0 3; 63 8 0 3; 64 9 0 3; 65 10 0 3; 66 11 0 3; 67 12 0 3;
68 13 0 3; 69 14 0 3; 70 15 0 3; 71 16 0 3; 72 0 0 4; 73 1 0 4; 74 2 0 4;
75 3 0 4; 76 4 0 4; 77 5 0 4; 78 6 0 4; 79 7 0 4; 80 8 0 4; 81 9 0 4;
82 10 0 4; 83 11 0 4; 84 12 0 4; 85 13 0 4; 86 14 0 4; 87 15 0 4; 88 16 0 4;
89 0 0 5; 90 1 0 5; 91 2 0 5; 92 3 0 5; 93 4 0 5; 94 5 0 5; 95 6 0 5; 96 7 0 5;
97 8 0 5; 98 9 0 5; 99 10 0 5; 100 11 0 5; 101 12 0 5; 102 13 0 5; 103 14 0 5;
104 15 0 5; 105 16 0 5; 106 0 0 6; 107 1 0 6; 108 2 0 6; 109 3 0 6; 110 4 0 6;
111 5 0 6; 112 6 0 6; 113 7 0 6; 114 8 0 6; 115 9 0 6; 116 10 0 6; 117 11 0 6;
118 12 0 6; 119 13 0 6; 120 14 0 6; 121 15 0 6; 122 16 0 6; 123 0 0 7;
124 1 0 7; 125 2 0 7; 126 3 0 7; 127 4 0 7; 128 5 0 7; 129 6 0 7; 130 7 0 7;
131 8 0 7; 132 9 0 7; 133 10 0 7; 134 11 0 7; 135 12 0 7; 136 13 0 7;
137 14 0 7; 138 15 0 7; 139 16 0 7; 140 0 0 8; 141 1 0 8; 142 2 0 8; 143 3 0 8;
144 4 0 8; 145 5 0 8; 146 6 0 8; 147 7 0 8; 148 8 0 8; 149 9 0 8; 150 10 0 8;
151 11 0 8; 152 12 0 8; 153 13 0 8; 154 14 0 8; 155 15 0 8; 156 16 0 8;
157 0 0 9; 158 1 0 9; 159 2 0 9; 160 3 0 9; 161 4 0 9; 162 5 0 9; 163 6 0 9;
164 7 0 9; 165 8 0 9; 166 9 0 9; 167 10 0 9; 168 11 0 9; 169 12 0 9;
170 13 0 9; 171 14 0 9; 172 15 0 9; 173 16 0 9; 174 0 0 10; 175 1 0 10;
176 2 0 10; 177 3 0 10; 178 4 0 10; 179 5 0 10; 180 6 0 10; 181 7 0 10;
182 8 0 10; 183 9 0 10; 184 10 0 10; 185 11 0 10; 186 12 0 10; 187 13 0 10;
188 14 0 10; 189 15 0 10; 190 16 0 10; 191 0 0 11; 192 1 0 11; 193 2 0 11;
194 3 0 11; 195 4 0 11; 196 5 0 11; 197 6 0 11; 198 7 0 11; 199 8 0 11;
200 9 0 11; 201 10 0 11; 202 11 0 11; 203 12 0 11; 204 13 0 11; 205 14 0 11;
206 15 0 11; 207 16 0 11; 208 0 0 12; 209 1 0 12; 210 2 0 12; 211 3 0 12;
212 4 0 12; 213 5 0 12; 214 6 0 12; 215 7 0 12; 216 8 0 12; 217 9 0 12;
218 10 0 12; 219 11 0 12; 220 12 0 12; 221 13 0 12; 222 14 0 12; 223 15 0 12;
224 16 0 12; 225 0 0 13; 226 1 0 13; 227 2 0 13; 228 3 0 13; 229 4 0 13;
230 5 0 13; 231 6 0 13; 232 7 0 13; 233 8 0 13; 234 9 0 13; 235 10 0 13;
236 11 0 13; 237 12 0 13; 238 13 0 13; 239 14 0 13; 240 15 0 13; 241 16 0 13;
242 0 0 14; 243 1 0 14; 244 2 0 14; 245 3 0 14; 246 4 0 14; 247 5 0 14;
248 6 0 14; 249 7 0 14; 250 8 0 14; 251 9 0 14; 252 10 0 14; 253 11 0 14;
254 12 0 14; 255 13 0 14; 256 14 0 14; 257 15 0 14; 258 16 0 14; 259 0 0 15;
260 1 0 15; 261 2 0 15; 262 3 0 15; 263 4 0 15; 264 5 0 15; 265 6 0 15;
266 7 0 15; 267 8 0 15; 268 9 0 15; 269 10 0 15; 270 11 0 15; 271 12 0 15;
272 13 0 15; 273 14 0 15; 274 15 0 15; 275 16 0 15; 276 0 0 16; 277 1 0 16;
278 2 0 16; 279 3 0 16; 280 4 0 16; 281 5 0 16; 282 6 0 16; 283 7 0 16;
284 8 0 16; 285 9 0 16; 286 10 0 16; 287 11 0 16; 288 12 0 16; 289 13 0 16;
290 14 0 16; 291 15 0 16; 292 16 0 16; 300 0 2 9; 301 16.1 2 9; 302 0 2 7;
303 16.1 2 7; 304 8.05 2 9; 305 8.05 2 7; 306 9.05 2 7; 307 7.05 2 7;
308 9.05 2 9; 309 7.05 2 9;
MEMBER INCIDENCES
259 1 140; 260 3 156; 271 300 157; 272 301 173; 273 302 123; 274 303 139;
279 303 3; 280 301 3; 281 302 1; 282 1 300; 283 300 309; 284 304 308;
286 302 307; 287 305 306; 289 306 303; 290 132 306; 291 307 305; 292 130 307;
293 308 301; 294 166 308; 295 309 304; 296 164 309;
ELEMENT INCIDENCES SHELL
3 4 6 7 5; 4 6 8 9 7; 5 8 10 11 9; 6 10 12 13 11; 7 12 14 15 13; 8 14 16 17 15;
9 16 18 19 17; 10 18 20 21 19; 11 20 22 23 21; 12 22 24 25 23; 13 24 26 27 25;
14 26 28 29 27; 15 28 30 31 29; 16 30 32 33 31; 17 32 34 35 33; 18 34 36 37 35;
19 5 7 39 38; 20 7 9 40 39; 21 9 11 41 40; 22 11 13 42 41; 23 13 15 43 42;
24 15 17 44 43; 25 17 19 45 44; 26 19 21 46 45; 27 21 23 47 46; 28 23 25 48 47;
29 25 27 49 48; 30 27 29 50 49; 31 29 31 51 50; 32 31 33 52 51; 33 33 35 53 52;
34 35 37 54 53; 35 38 39 56 55; 36 39 40 57 56; 37 40 41 58 57; 38 41 42 59 58;
39 42 43 60 59; 40 43 44 61 60; 41 44 45 62 61; 42 45 46 63 62; 43 46 47 64 63;
44 47 48 65 64; 45 48 49 66 65; 46 49 50 67 66; 47 50 51 68 67; 48 51 52 69 68;
49 52 53 70 69; 50 53 54 71 70; 51 55 56 73 72; 52 56 57 74 73; 53 57 58 75 74;
54 58 59 76 75; 55 59 60 77 76; 56 60 61 78 77; 57 61 62 79 78; 58 62 63 80 79;
59 63 64 81 80; 60 64 65 82 81; 61 65 66 83 82; 62 66 67 84 83; 63 67 68 85 84;
64 68 69 86 85; 65 69 70 87 86; 66 70 71 88 87; 67 72 73 90 89; 68 73 74 91 90;
69 74 75 92 91; 70 75 76 93 92; 71 76 77 94 93; 72 77 78 95 94; 73 78 79 96 95;
74 79 80 97 96; 75 80 81 98 97; 76 81 82 99 98; 77 82 83 100 99;
78 83 84 101 100; 79 84 85 102 101; 80 85 86 103 102; 81 86 87 104 103;
82 87 88 105 104; 83 89 90 107 106; 84 90 91 108 107; 85 91 92 109 108;
86 92 93 110 109; 87 93 94 111 110; 88 94 95 112 111; 89 95 96 113 112;
90 96 97 114 113; 91 97 98 115 114; 92 98 99 116 115; 93 99 100 117 116;
94 100 101 118 117; 95 101 102 119 118; 96 102 103 120 119; 97 103 104 121 120;
98 104 105 122 121; 99 106 107 124 123; 100 107 108 125 124;
101 108 109 126 125; 102 109 110 127 126; 103 110 111 128 127;
104 111 112 129 128; 105 112 113 130 129; 106 113 114 131 130;
107 114 115 132 131; 108 115 116 133 132; 109 116 117 134 133;
110 117 118 135 134; 111 118 119 136 135; 112 119 120 137 136;
113 120 121 138 137; 114 121 122 139 138; 115 123 124 141 140;
116 124 125 142 141; 117 125 126 143 142; 118 126 127 144 143;
119 127 128 145 144; 120 128 129 146 145; 121 129 130 147 146;
122 130 131 148 147; 123 131 132 149 148; 124 132 133 150 149;
125 133 134 151 150; 126 134 135 152 151; 127 135 136 153 152;
128 136 137 154 153; 129 137 138 155 154; 130 138 139 156 155;
131 140 141 158 157; 132 141 142 159 158; 133 142 143 160 159;
134 143 144 161 160; 135 144 145 162 161; 136 145 146 163 162;
137 146 147 164 163; 138 147 148 165 164; 139 148 149 166 165;
140 149 150 167 166; 141 150 151 168 167; 142 151 152 169 168;
143 152 153 170 169; 144 153 154 171 170; 145 154 155 172 171;
146 155 156 173 172; 147 157 158 175 174; 148 158 159 176 175;
149 159 160 177 176; 150 160 161 178 177; 151 161 162 179 178;
152 162 163 180 179; 153 163 164 181 180; 154 164 165 182 181;
155 165 166 183 182; 156 166 167 184 183; 157 167 168 185 184;
158 168 169 186 185; 159 169 170 187 186; 160 170 171 188 187;
161 171 172 189 188; 162 172 173 190 189; 163 174 175 192 191;
164 175 176 193 192; 165 176 177 194 193; 166 177 178 195 194;
167 178 179 196 195; 168 179 180 197 196; 169 180 181 198 197;
170 181 182 199 198; 171 182 183 200 199; 172 183 184 201 200;
173 184 185 202 201; 174 185 186 203 202; 175 186 187 204 203;
176 187 188 205 204; 177 188 189 206 205; 178 189 190 207 206;
179 191 192 209 208; 180 192 193 210 209; 181 193 194 211 210;
182 194 195 212 211; 183 195 196 213 212; 184 196 197 214 213;
185 197 198 215 214; 186 198 199 216 215; 187 199 200 217 216;
188 200 201 218 217; 189 201 202 219 218; 190 202 203 220 219;
191 203 204 221 220; 192 204 205 222 221; 193 205 206 223 222;
194 206 207 224 223; 195 208 209 226 225; 196 209 210 227 226;
197 210 211 228 227; 198 211 212 229 228; 199 212 213 230 229;
200 213 214 231 230; 201 214 215 232 231; 202 215 216 233 232;
203 216 217 234 233; 204 217 218 235 234; 205 218 219 236 235;
206 219 220 237 236; 207 220 221 238 237; 208 221 222 239 238;
209 222 223 240 239; 210 223 224 241 240; 211 225 226 243 242;
212 226 227 244 243; 213 227 228 245 244; 214 228 229 246 245;
215 229 230 247 246; 216 230 231 248 247; 217 231 232 249 248;
218 232 233 250 249; 219 233 234 251 250; 220 234 235 252 251;
221 235 236 253 252; 222 236 237 254 253; 223 237 238 255 254;
224 238 239 256 255; 225 239 240 257 256; 226 240 241 258 257;
227 242 243 260 259; 228 243 244 261 260; 229 244 245 262 261;
230 245 246 263 262; 231 246 247 264 263; 232 247 248 265 264;
233 248 249 266 265; 234 249 250 267 266; 235 250 251 268 267;
236 251 252 269 268; 237 252 253 270 269; 238 253 254 271 270;
239 254 255 272 271; 240 255 256 273 272; 241 256 257 274 273;
242 257 258 275 274; 243 259 260 277 276; 244 260 261 278 277;
245 261 262 279 278; 246 262 263 280 279; 247 263 264 281 280;
248 264 265 282 281; 249 265 266 283 282; 250 266 267 284 283;
251 267 268 285 284; 252 268 269 286 285; 253 269 270 287 286;
254 270 271 288 287; 255 271 272 289 288; 256 272 273 290 289;
257 273 274 291 290; 258 274 275 292 291;
ELEMENT PROPERTY
3 TO 258 THICKNESS 2.167
DEFINE MATERIAL START
ISOTROPIC STEEL
E 4.176e+006
POISSON 0.3
DENSITY 0.489024
ALPHA 6e-006
DAMP 0.03
TYPE STEEL
STRENGTH FY 5184 FU 8352 RY 1.5 RT 1.2
ISOTROPIC CONCRETE
E 453600
POISSON 0.17
DENSITY 0.150336
ALPHA 5e-006
DAMP 0.05
TYPE CONCRETE
G 193846
TYPE CONCRETE
STRENGTH FCU 720
STRENGTH FCU 576
END DEFINE MATERIAL
MEMBER PROPERTY AMERICAN
259 260 271 TO 274 279 TO 284 286 287 289 TO 296 TABLE ST W12X40
CONSTANTS
MATERIAL STEEL MEMB 259 260 271 TO 274 279 TO 284 286 287 289 TO 296
MATERIAL CONCRETE MEMB 3 TO 258
SUPPORTS
4 TO 292 ELASTIC MAT DIRECT Y SUBGRADE 100 PRINT
DEFINE MOVING LOAD
*Live + Impact * 1.4
TYPE 1 LOAD 49.5 49.5 49.5 49.5
DIST -5 -6 -5
*Braking * 1.4
TYPE 2 LOAD 11 4 4 11
DIST -5 -6 -5
*Traction * 1.4
TYPE 3 LOAD 6.5 2.5 2.5 6.5
DIST -5 -6 -5
TYPE 4 LOAD 7.5 7.5 7.5 7.5
DIST -5 -6 -5
TYPE 5 LOAD 11.5 11.5 11.5 11.5
DIST -5 -6 -5
*DL*1.4
LOAD 1 LOADTYPE Dead TITLE DL
MEMBER LOAD
283 284 286 287 289 291 293 295 UNI GY -0.28
LOAD GENERATION 34 ADD LOAD 1
TYPE 1 0 2 7 XINC 1
TYPE 2 0 2 7 XINC 1
TYPE 4 0 2 7 XINC 1
TYPE 1 0 2 9 XINC 1
TYPE 2 0 2 9 XINC 1
TYPE 4 0 2 9 XINC 1
LOAD GENERATION 34 ADD LOAD 1
TYPE 1 0 2 7 XINC 1
TYPE 3 0 2 7 XINC 1
TYPE 5 0 2 7 XINC 1
TYPE 1 0 2 9 XINC 1
TYPE 3 0 2 9 XINC 1
TYPE 5 0 2 9 XINC 1
PERFORM ANALYSIS
START CONCRETE DESIGN
CODE ACI
CLB 0.25 MEMB 3 TO 258
FC 576 MEMB 3 TO 258
FYMAIN 7200 MEMB 3 TO 258
DESIGN ELEMENT 3 TO 258
END CONCRETE DESIGN
FINISH

Hello,

I am modeling a PT flat plate slab in RAM Concept. Actually, I am modeling an existing building. Is there a way I can input user defined SSR for punching shear? I am trying to model and match the existing stud rail. Thank you, 

Hello,

I have created a Ram model that is crashing. When I run the integrity check on the Ram Modeler module is does not show any warnings or error, but every time I click the "Design All" button on Ram Beam it crashes. I found in the forum that there may have been a bug in the v16.00.00 version that we were running, which could cause a similar problem (https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/40890/ram-steel-beam-crashes-with-connect-licensing). Since finding this problem, I have downloaded the latest version v16.01.00.20 but the issue is still present.

I would appreciate any help with potential fixes.

I've been getting web crippling errors for my light gauge joist framing in Ram Elements. I have increased the bearing of the joist to a 6" bearing, the width of the bearing wall below. It is still failing, I have not found any information on how to resolve the issue. Any ideas?

Dear all while defining the  seismic parameters in load definition the toolbar is blank 
can any one guide me how to resolve the issue??

Dear Sir/Miss,

According to question in this website https://communities.bentley.com/products/ram-staad/f/ram-staad-forum/108249/base-shear-value-in-response-spectrum-analysis.

There are two value of base shear, spectrum base shear(smaller) and support reaction(larger) .

Which one should I choose to design foundation while superstructure run spectrum?

Best Regard,

Dora.

Good afternoon.

I used DFF and SELECT command to check a serviceability as shown below.

DEFINE ENVELOPE

201 TO 276 ENVELOPE 2 TYPE STRENGTH

901 ENVELOPE 8 TYPE SERVICEABILITY

END DEFINE ENVELOPE

**********************************************************************

LOAD LIST 201 TO 276

LOAD LIST ENV 8

PARAMETER 1

CODE AISC UNIFIED 2010

METHOD LRFD

FYLD 245000 MEMB _STEEL

DFF 200 ALL

DJ1 4 MEMB 4 31

DJ2 24 MEMB 4 31

DMIN 0.19 MEMB _STEEL

**********************************************************************

TRACK 2 MEMB _STEEL

CHECK CODE MEMB _STEEL

SELECT MEMB _RSG

*********************************************************************

FINISH

The code checking result is 'Pass' by 0.316 ratio with H194x150x6x9 section and relatively small deflection as shown below.

                       STAAD.PRO CODE CHECKING - (AISC-360-10-LRFD)   v1.4a
                       ********************************************

 MEMBER     TABLE       RESULT/   CRITICAL COND/     RATIO/     LOADING/
                          FX            MY             MZ       LOCATION
 =======================================================================
 

       4 ST   H194X150X6X9             (JAPANESE SECTIONS)
                           PASS   DEFLECTION           0.316       901
                        8.29            0.07          13.46        5.02
|-----------------------------------------------------------------------|
| DEFLECTION CHECK:   (UNIT: CM  )                                      |
|                                                                       |
| Limit Span/Deflection (DFF) :  200.000   Limit      :     2.512       |
| Span/Deflection             :  6.32E+02  Deflection :     0.795       |
| L/C                         :   901      LOC        :     5.025       |
| Ratio                       :     0.316  (PASS)                       |
|-----------------------------------------------------------------------|

Even if the ratio is below 1.0, MEMBER SELECTION command find the huge section which is H498x432x45x70 for all members as shown below.

I expected the section not be changed because the ratio is below 1.0.

I have not defined any restriction for section so dont know why this big section is selected.

                     STAAD.PRO MEMBER SELECTION - (AISC-360-10-LRFD)   v1.4a
                     ***********************************************

 MEMBER     TABLE       RESULT/   CRITICAL COND/     RATIO/     LOADING/
                          FX            MY             MZ       LOCATION
 =======================================================================
 

       4 ST   H498x432x45x70           (JAPANESE SECTIONS)
                           PASS   DEFLECTION           0.007       901
                        8.29            0.07          13.46        5.02
|-----------------------------------------------------------------------|
| DEFLECTION CHECK:   (UNIT: CM  )                                      |
|                                                                       |
| Limit Span/Deflection (DFF) :  200.000   Limit      :     2.512       |
| Span/Deflection             :  2.86E+04  Deflection :     0.018       |
| L/C                         :   901      LOC        :     5.025       |
| Ratio                       :     0.007  (PASS)                       |
|-----------------------------------------------------------------------|

Can you help me to resolve the problem?

Thanks.

Dear all 

In RCDC when we design Raft Footing ,why software is not creating a combine raft instead of which it is giving result for the isolated footing with a step formation. 

My beam member 14, 19 and 30 are failing deflection check (UC 54.1 and 40.4) with minimal loads. The maximum node displacement for the frame is 0.225 in. If you can provide some guidance. I am attaching my model file. Thanks. 

communities.bentley.com/.../sand-dunes-utility-cooler-5_2D00_17_2D00_2019-DJ1DJ2.STD