UNT and UNB

Yes , your assumption is correct. In this case , UNB should be ideally L if the bottom flange is not constraint anywhere at the intermediate location.

When your concrete slab has has a beam top flange embedded within then the UNB  should be L if the bottom flange only has been restrained laterally at the member ends

Is UNT and UNB unbraced length of top and bottom flange regardless if in compression or tension?

or UNT and UNB is unbraced length of top and bottom flange that is in compression?

UNT and UNB are the unbraced length of the top and the bottom flange. The program figures out which flange is in compression and accordingly uses either of UNT or UNB. For the British and the Eurocodes, we have UNL - which specifies the unbraced length of the compression flange.

PLEASE TELL ME WHAT WILL BE THE VALUE OF UBN AND UNT

STAAD SPACE

START JOB INFORMATION
ENGINEER DATE 21-Aug-16
END JOB INFORMATION
INPUT WIDTH 79
UNIT METER KN
JOINT COORDINATES
1 0 -0.29 0; 2 0 6.45 0; 3 36.6 -0.29 0; 4 36.6 6.45 0; 5 36.6 -0.29 11.7;
6 36.6 6.45 11.7; 7 18.3 -0.29 11.7; 8 18.3 7.73 11.7; 9 18.3 -0.29 3.7;
10 18.3 7.73 3.7; 11 18.3 -0.29 0; 12 18.3 7.73 0; 13 0 -0.29 3.7;
14 0 6.45 3.7; 15 36.6 -0.29 3.7; 16 36.6 6.45 3.7; 17 0 -0.29 11.7;
18 0 6.45 11.7; 22 7 -0.29 0; 23 12.3 -0.29 0; 25 24.3 -0.29 0;
26 29.6 -0.29 0; 27 36.6 -0.29 19.7; 28 36.6 6.45 19.7; 29 18.3 -0.29 19.7;
30 18.3 7.73 19.7; 31 0 -0.29 19.7; 32 0 6.45 19.7; 33 6.98294 6.93842 0;
34 12.27 7.30823 0; 35 29.6171 6.93842 0; 36 24.33 7.30823 0;
37 36.6 -0.29 27.7; 38 36.6 6.45 27.7; 39 18.3 -0.29 27.7; 40 18.3 7.73 27.7;
41 0 -0.29 27.7; 42 0 6.45 27.7; 43 36.6 -0.29 35.7; 44 36.6 6.45 35.7;
45 18.3 -0.29 35.7; 46 18.3 7.73 35.7; 47 0 -0.29 35.7; 48 0 6.45 35.7;
49 36.6 -0.29 43.7; 50 36.6 6.45 43.7; 51 18.3 -0.29 43.7; 52 18.3 7.73 43.7;
53 0 -0.29 43.7; 54 0 6.45 43.7; 55 36.6 -0.29 49.4; 56 36.6 6.45 49.4;
57 18.3 -0.29 49.4; 58 18.3 7.73 49.4; 59 0 -0.29 49.4; 60 0 6.45 49.4;
61 6.98294 6.93842 49.4; 62 7 -0.29 49.4; 63 12.27 7.30823 49.4;
64 12.3 -0.29 49.4; 65 24.33 7.30823 49.4; 66 24.3 -0.29 49.4;
67 29.6171 6.93842 49.4; 68 29.6 -0.29 49.4; 69 6.1 6.87667 3.7;
72 30.5 6.87667 3.7; 73 6.99 6.87667 43.7; 74 12.2 7.30333 43.7;
75 24.4 7.30333 43.7; 76 29.61 6.87667 43.7; 77 6.1 6.87667 0;
80 30.5 6.87667 0; 81 24.2854 7.31135 3.7; 82 12.3146 7.31135 3.7;
83 6.1 6.87667 19.7; 84 12.2 7.30333 19.7; 85 24.4 7.30333 19.7;
86 30.5 6.87667 19.7; 87 6.1 6.87667 27.7; 88 12.2 7.30333 27.7;
89 24.4 7.30333 27.7; 90 30.5 6.87667 27.7; 91 6.1 6.87667 11.7;
92 12.2 7.30333 11.7; 93 24.4 7.30333 11.7; 94 30.5 6.87667 11.7;
95 6.1 6.87667 35.7; 96 12.2 7.30333 35.7; 97 24.4 7.30333 35.7;
98 30.5 6.87667 35.7; 99 1.49721 6.54139 43.7; 100 1.49634 6.55466 11.7;
101 1.49634 6.55466 3.7; 102 1.49634 6.55466 19.7; 103 1.49634 6.55466 0;
104 1.49634 6.55466 27.7; 105 1.49634 6.55466 35.7; 106 1.49634 6.55466 49.4;
107 35.1037 6.55466 49.4; 108 35.0998 6.54157 43.7; 109 35.0988 6.55501 3.7;
110 35.0988 6.55501 0; 111 35.0988 6.55501 19.7; 112 35.0988 6.55501 27.7;
113 35.0988 6.555 11.7; 114 35.0988 6.555 35.7; 132 0 3.08 15.7;
133 0 3.08 31.7; 134 36.6 3.08 46.55; 135 36.6 3.08 31.7; 136 36.6 3.08 15.7;
137 36.6 3.08 1.85; 138 3.05 6.66333 1.85; 139 15.2962 7.5199 1.85687;
140 21.3038 7.5199 1.85687; 141 33.55 6.66333 1.85; 142 15.2676 7.5179 46.5664;
143 21.3324 7.5179 46.5664; 144 3.05 6.66333 15.7; 145 15.25 7.51666 15.7;
146 21.35 7.51666 15.7; 147 33.55 6.66333 15.7; 148 3.05 6.66333 31.7;
149 15.25 7.51666 31.7; 150 21.35 7.51666 31.7; 151 33.55 6.66333 31.7;
152 9.15 7.09 31.7; 153 27.45 7.09 31.7; 154 9.15 7.09 15.7;
155 27.45 7.09 15.7; 156 9.19611 7.09323 1.84334; 157 27.4039 7.09323 1.84334;
158 16.8036 7.62534 49.4; 159 19.7964 7.62534 11.7; 160 19.7964 7.62534 19.7;
161 19.7964 7.62534 0; 162 19.7964 7.62534 27.7; 163 19.7964 7.62534 35.7;
164 19.7964 7.62534 43.7; 165 19.7964 7.62534 49.4; 166 19.7964 7.62534 3.7;
167 16.8036 7.62534 43.7; 168 16.8036 7.62534 35.7; 169 16.8036 7.62534 27.7;
170 16.8036 7.62534 19.7; 171 16.8036 7.62534 11.7; 172 16.8036 7.62534 0;
173 16.8036 7.62534 3.7; 174 16.0056 7.56952 49.4;
MEMBER INCIDENCES
1 1 2; 2 3 4; 3 5 6; 4 7 8; 5 9 10; 6 11 12; 7 13 14; 8 15 16; 9 17 18;
10 18 100; 12 14 101; 26 12 10; 27 10 8; 29 27 28; 30 29 30; 31 31 32;
32 32 102; 35 8 30; 38 2 103; 42 35 80; 44 33 22; 45 34 23; 46 36 25; 47 35 26;
51 30 40; 54 37 38; 55 39 40; 56 41 42; 57 42 104; 65 43 44; 66 45 46;
67 47 48; 68 48 105; 76 49 50; 77 51 52; 78 53 54; 79 54 99; 81 55 56;
82 57 58; 83 59 60; 84 60 106; 87 52 58; 89 61 63; 90 61 62; 92 63 64;
93 65 67; 94 65 66; 95 67 107; 96 67 68; 100 72 109; 101 73 74; 103 75 76;
104 76 108; 105 77 33; 108 80 110; 109 33 34; 111 81 72; 113 82 69; 114 36 35;
139 83 84; 141 85 86; 142 86 111; 143 87 88; 145 89 90; 146 90 112; 195 18 132;
196 32 132; 197 42 133; 198 48 133; 199 50 134; 200 56 134; 201 37 135;
202 38 135; 203 6 136; 204 28 136; 205 3 137; 206 4 137; 207 2 138; 209 34 139;
210 14 138; 212 82 139; 213 10 140; 215 72 141; 216 12 140; 218 80 141;
231 60 73; 233 63 142; 234 52 143; 236 76 56; 237 54 61; 239 74 142;
240 58 143; 242 67 50; 243 91 92; 245 93 94; 246 94 113; 247 95 96; 249 97 98;
250 98 114; 251 32 144; 253 84 145; 254 8 146; 256 94 147; 257 6 147;
259 93 146; 260 30 145; 262 83 144; 263 42 148; 265 88 149; 266 46 150;
268 98 151; 270 97 150; 271 40 149; 273 87 148; 274 90 151; 275 99 73;
276 100 91; 277 101 69; 278 102 83; 279 103 77; 280 104 87; 281 105 95;
282 106 61; 290 44 114; 291 50 108; 292 38 112; 293 28 111; 294 6 113;
295 16 109; 296 4 110; 297 56 107; 324 14 18; 325 2 14; 326 18 32; 327 32 42;
328 42 48; 329 48 54; 330 16 6; 331 6 28; 332 28 38; 333 38 44; 334 44 50;
335 4 16; 336 50 56; 337 54 60; 338 46 52; 339 40 46; 352 61 74; 353 73 63;
354 75 67; 355 76 65; 356 87 152; 357 88 152; 358 97 153; 359 89 153;
360 91 154; 361 92 154; 362 93 155; 363 94 155; 364 77 156; 365 34 156;
366 36 157; 367 80 157; 368 132 31; 369 132 17; 370 133 47; 371 133 41;
372 134 55; 373 134 49; 374 135 44; 375 135 43; 376 136 27; 377 136 5;
378 137 16; 379 137 15; 380 138 69; 381 139 10; 382 138 77; 383 139 12;
384 140 36; 385 141 4; 386 140 81; 387 141 16; 388 142 52; 389 143 65;
390 142 58; 391 143 75; 392 144 91; 393 145 8; 394 146 85; 395 147 28;
396 147 86; 397 146 30; 398 145 92; 399 144 18; 400 148 95; 401 149 46;
402 150 89; 403 151 38; 404 150 40; 405 149 96; 406 148 48; 407 151 44;
408 152 96; 409 152 95; 410 153 90; 411 153 98; 412 154 84; 413 154 83;
414 155 86; 415 155 85; 416 156 82; 417 156 69; 418 157 72; 419 157 81;
420 158 174; 421 159 93; 422 160 85; 423 161 36; 424 162 89; 425 163 97;
426 164 75; 427 165 65; 428 166 81; 429 167 74; 430 168 96; 431 169 88;
432 170 84; 433 171 92; 434 172 34; 435 173 82; 436 174 63; 437 58 158;
438 58 165; 439 52 164; 447 46 163; 448 40 162; 449 30 160; 450 8 159;
451 10 166; 452 12 161; 453 52 167; 454 46 168; 455 40 169; 456 30 170;
457 8 171; 458 10 173; 459 12 172;
DEFINE MATERIAL START
ISOTROPIC STEEL
E 2.15e+008
POISSON 0.3
DENSITY 75.8195
ALPHA 1.2e-005
DAMP 0.03
ISOTROPIC STAINLESSSTEEL
E 1.9793e+008
POISSON 0.3
DENSITY 76.8195
ALPHA 1.8e-005
DAMP 0.03
ISOTROPIC CONCRETE
E 2.17185e+007
POISSON 0.17
DENSITY 23.5616
ALPHA 1e-005
DAMP 0.05
TYPE CONCRETE
STRENGTH FCU 27579
END DEFINE MATERIAL
MEMBER PROPERTY BRITISH
1 TO 9 29 TO 31 54 TO 56 65 TO 67 76 TO 78 81 TO 83 TABLE ST UB610X229X113
42 89 93 95 100 101 103 TO 105 108 109 111 113 114 275 277 279 282 420 423 -
426 TO 429 434 TO 436 TABLE ST UB533X210X82
MEMBER PROPERTY BRITISH
26 27 35 51 87 324 TO 339 TABLE ST PIP1146.0
44 TO 47 90 92 94 96 TABLE ST UC203X203X52
139 141 TO 143 145 146 243 245 TO 247 249 250 276 278 280 281 421 422 424 -
425 430 TO 433 TABLE ST UB533X210X101
MEMBER PROPERTY BRITISH
10 12 32 38 57 68 79 84 290 TO 297 437 TO 439 447 TO 458 -
459 TAPERED 1 0.01 0.533 0.21 0.014 0.21 0.014
195 TO 207 209 210 212 213 215 216 218 231 233 234 236 237 239 240 242 251 -
253 254 256 257 259 260 262 263 265 266 268 270 271 273 274 352 TO 418 -
419 TABLE ST PIP603.2
CONSTANTS
BETA 90 MEMB 44 TO 47 90 92 94 96
MATERIAL STEEL ALL
SUPPORTS
1 3 5 7 9 11 13 15 17 22 23 25 TO 27 29 31 37 39 41 43 45 47 49 51 53 55 57 -
59 62 64 66 68 PINNED
LOAD 1 LOADTYPE Dead TITLE DL
SELFWEIGHT Y -1
MEMBER LOAD
38 42 105 108 109 114 279 296 423 434 452 459 UNI GY -2
10 32 57 68 139 141 TO 143 145 146 243 245 TO 247 249 250 276 278 280 281 -
290 292 TO 294 421 422 424 425 430 TO 433 447 TO 450 454 TO 457 UNI GY -8
84 89 93 95 282 297 420 427 436 TO 438 UNI GY -2.85
79 101 103 104 275 291 426 429 439 453 UNI GY -6.85
12 100 111 113 277 295 428 435 451 458 UNI Y -5.6
LOAD 2 LOADTYPE Live TITLE LL
MEMBER LOAD
38 42 105 108 109 114 279 296 423 434 452 459 UNI GY -1.38
12 100 111 113 277 295 428 435 451 458 UNI GY -4.38
10 32 57 68 139 141 TO 143 145 146 243 245 TO 247 249 250 276 278 280 281 -
290 292 TO 294 421 422 424 425 430 TO 433 447 TO 450 454 TO 457 UNI GY -6
79 101 103 104 275 291 426 429 439 453 UNI GY -5.13
84 89 93 95 282 297 420 427 436 TO 438 UNI GY -2.13
**
**
**
LOAD 3 LOADTYPE Wind TITLE WL
MEMBER LOAD
2 UNI GX -2.22
8 UNI GX -7.02
3 29 54 65 UNI GX -9.6
76 UNI GX -8.22
81 UNI GX -3.42
1 UNI GX -1.85
7 UNI GX -7.02
9 31 56 67 UNI GX -8
78 UNI GX -6.85
83 UNI GX -3.42
1 2 UNI GZ -3.95
45 46 UNI GZ -6.38
6 UNI GZ -6.78
44 47 UNI GZ -6.94
81 83 UNI GZ 3.95
90 96 UNI GZ 6.94
92 94 UNI GZ 6.38
82 UNI GZ 6.78
79 101 103 104 275 291 426 429 439 453 UNI GY 8.76
84 89 93 95 282 297 420 427 436 TO 438 UNI GY 3.64
38 42 105 108 109 114 279 296 423 434 452 459 UNI GY 2.36
12 100 111 113 277 295 428 435 451 458 UNI GY 7.48
10 32 57 68 139 141 TO 143 145 146 243 245 TO 247 249 250 276 278 280 281 -
290 292 TO 294 421 422 424 425 430 TO 433 447 TO 450 454 TO 456 -
457 UNI GY 10.24
LOAD 4 LOADTYPE Wind TITLE WIND LOAD Z
MEMBER LOAD
1 2 6 44 TO 47 81 TO 83 90 92 94 96 UNI GZ -5
***WALL***
***WINDWARD**
**
LOAD COMB 5 GENERATED AISC PUBLIC 1
1 1.4
LOAD COMB 6 GENERATED AISC PUBLIC 2
1 1.2 2 1.6
LOAD COMB 7 GENERATED AISC PUBLIC 3
1 1.2 2 0.5
LOAD COMB 8 GENERATED AISC PUBLIC 4
1 1.2 3 0.8
LOAD COMB 9 GENERATED AISC PUBLIC 5
1 1.2 4 0.8
LOAD COMB 10 GENERATED AISC PUBLIC 6
1 1.2 2 0.5 3 1.6
LOAD COMB 11 GENERATED AISC PUBLIC 7
1 1.2 2 0.5 4 1.6
LOAD COMB 12 GENERATED AISC PUBLIC 8
1 0.9 3 1.6
LOAD COMB 13 GENERATED AISC PUBLIC 9
1 0.9 4 1.6
LOAD COMB 14 GENERATED AISC PUBLIC 10
1 0.9
PDELTA ANALYSIS SMALLDELTA
PARAMETER 3
CODE LRFD
FYLD 355000 ALL
FU 520000 ALL
LY 4.86 MEMB 1 TO 10 12 29 TO 32 38 42 44 TO 47 54 TO 57 65 TO 68 76 TO 79 -
81 TO 84 89 90 92 TO 96 100 101 103 TO 105 108 109 111 113 114 139 -
141 TO 143 145 146 243 245 TO 247 249 250 275 TO 282 290 TO 297 420 TO 439 -
447 TO 459
UNB 1.5 MEMB 1 TO 10 12 29 TO 32 38 42 44 TO 47 54 TO 57 65 TO 68 76 TO 79 -
81 TO 84 89 90 92 TO 96 100 101 103 TO 105 108 109 111 113 114 139 -
141 TO 143 145 146 243 245 TO 247 249 250 275 TO 282 290 TO 297 420 TO 439 -
447 TO 459
UNT 1.5 MEMB 1 TO 10 12 29 TO 32 38 42 44 TO 47 54 TO 57 65 TO 68 76 TO 79 -
81 TO 84 89 90 92 TO 96 100 101 103 TO 105 108 109 111 113 114 139 -
141 TO 143 145 146 243 245 TO 247 249 250 275 TO 282 290 TO 297 420 TO 439 -
447 TO 459
KZ 2 MEMB 1 TO 9 29 TO 31 44 TO 47 54 TO 56 65 TO 67 76 78 81 TO 83 90 92 94 96
KY 1.2 MEMB 1 TO 9 29 TO 31 44 TO 47 54 TO 56 65 TO 67 76 TO 78 81 TO 83 90 -
92 94 96
CHECK CODE MEMB 1 TO 10 12 29 TO 32 38 42 44 TO 47 54 TO 57 65 TO 68 -
76 TO 79 81 TO 84 89 90 92 TO 96 100 101 103 TO 105 108 109 111 113 114 139 -
141 TO 143 145 146 243 245 TO 247 249 250 275 TO 282 290 TO 297 420 TO 439 -
447 TO 459
FINISH

By default STAAD.Pro uses the member length as UNT and UNB and the same can be good for the members which are in one piece like 141, 245 or any of the columns. So for these you do not need to specify the UNT and UNB as defaults are good. For the members which are split into segments like say member 421 and 450, 422 and 449 you may assign appropriate values. For example UNT/UNB could be 6.115 for each member if the entire length is unbraced.