Figure 1.
![Cold-formed steel frame with single-shear bolted connections [2]: a) geometry, b) detail “A” – structure of the truss joint, c) detail “B” and “C” – structure of the column, d) cross-section of the fastener before and after installation, e) view of the fastener before installation, f) cross-section of the fastener after installation](https://sciendo-parsed.s3.eu-central-1.amazonaws.com/64706ff583f1392090d69807/j_acee-2020-023_fig_001.jpg?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Content-Sha256=UNSIGNED-PAYLOAD&X-Amz-Credential=ASIA6AP2G7AKAV7KI53H%2F20251213%2Feu-central-1%2Fs3%2Faws4_request&X-Amz-Date=20251213T002335Z&X-Amz-Expires=3600&X-Amz-Security-Token=IQoJb3JpZ2luX2VjEEQaDGV1LWNlbnRyYWwtMSJHMEUCIQDKNa8y2lc0a0FpyiYuha1NvRqEFP6UmSLtJsox%2FjOcIAIgRf1VR%2F2z9TtrnD%2B1m2Vt%2FH2zcHfFeVyHGIPoaWRACgAqvQUIDRACGgw5NjMxMzQyODk5NDAiDGtbhLw3Wdws79NonSqaBSZ07EiTRHs0TsJ4mpDSApsikNHNkUTsM6tJ1ypQquKDvIFlQRWUtKwuwfFC6Z9Qjqyv5HM13kIXVXrEfdepp9Sy2MUd9XWK25MTx2V7uXsAKua6N5eb4zfBa1ghq2egZ1WQl6SIHLSrw8S6DOT0VWnaz5FJHfarUCokR9qmEoVUEIOTO%2BUlQBSNauCvKzRSmxNmp0zpnVi5kwv9%2FXMQaGOwMuaM4LiYhTmCy9fsWWVk0NEFeaRA3yg8tZX2FfuRlyoHQ2YW5czGNxIGHEgUSg4lwM8AQyAFVAParGUKmL9SBQ4TzugsER1xEppRIfLyhzerzwVQQ526PaVDEKXvMFyMtw7ONZkZqAGpa0M2aDWbZWg0joTQL8pg8CBNOTZFM%2BR86mEUFRNAuCWGBteSKHcxE%2Fw3ls7L36RPgR9DkvxJoCyUd5o4gf95iUetR3UURlD8BlQ9of9Z4WXGHnMB0Lm%2F4qObTUUdkb789UT2ua01I%2FfhTSeJuAnD%2B5GxBSK7sShhxxe2XdkCkexV1A8aF83TOZp%2F58wJ6CIcqtLrqKHbYPfxeH2HHyRXH5K1QiMD3i8ox69eW9Mf4M%2FwCiuGkWN43%2FvfGCtH7dkna4HWEhRl26So0CAYKedoZ%2FI8ekFkXmVOoC%2BMS02UD%2FIljhtZTDV71oUTPougTD69Dh5LZSaNSkymyDsrigqCueg6yIV6gyJv%2FzWWxRFzNsz9oSuDRyGO1ONrYYf7XRpii%2Bp1QDQjiYt4zjHmYIvY2bE4Z9JrjJARwNe2iEbwXxdjK%2FtBRGGzo5nQiWVCDW54y3UWyJ3gF4FOZy2xoDTCHnlcio49EGimyfuS9yhd9E6es3lOis5SgYkN7hLQfXavcHqC17Db3LzMvnedwuBpSDCm6%2FHJBjqxAdh7oddhjlgp8XvcZM%2Fwz76vAR7667PA6svUpsHSgIi0Eecm3ayDY8IZ2m3nbkGe6Y6XbroL2Ty3B8JFqSZKoqIAznrHvmk5ALuNzWf5Xo6Gf%2FMOh2hLVoK1sflhAjVz2sstjGqy6%2F0ETMaKS6O%2FJBnfcpmBfX6h1djmwbWmBsF389tmKZ1pB3Ew5SohucOZY2c8wsrkU1hQnz5aVOUoAYjPd0rOTek6eirHpxCi%2B2uv3g%3D%3D&X-Amz-Signature=24db0a72a90b81a95bbdcaa5e870dc87d29aacd0766bae5b29495406b39e788a&X-Amz-SignedHeaders=host&x-amz-checksum-mode=ENABLED&x-id=GetObject)
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Test results for specimens M16_4/0 without washers
| Specimen | Number of washers w | (Fmax) [kN] | δ (Fmax) [mm] | Bearing factor acc. to test Fmax/2fudt | Bearing factor acc. to EC3 [10] k 1 αb | Characteristic bearing resistance acc. to EC3 [10] 2Fb,Rk = 2k 1 αb fudt[kN] | Fmax /(2Fb,RK )]·100% |
|---|---|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
| M16.4/0-1 | 0 | 101.6 | 15.8 | 2.19 | 2.31 | 107.2 | 95 |
| M16.4/0-2 | 96.7 | 16.6 | 2.08 | 90 | |||
| M16.4/0-3 | 103.3 | 14.3 | 2.23 | 96 | |||
| M16.4/0-4 | 102.1 | 16.8 | 2.20 | 95 | |||
| M16.4/0-5 | 101.6 | 16.8 | 2.19 | 95 |
Comparison of bearing factors for specimens with M16 bolts and blind fasteners BOM R16
| Bearing factor | Differences [%] | |||
|---|---|---|---|---|
| aF,b/fudt | aF,bb/fud0t | |||
| M16.4/2 w = 2 | M16.4/0 w = 0 | B0M-S.4 B0M-KSW.4 | [(l)/(3)-l]-100% | [(2)/(3)-l]·100% |
| 1 | 2 | 3 | 4 | 5 |
| 2.371) | 2.183) | 2.004) | 18.5 | 9.0 |
Nodal forces in frame for various types of joint model
| Node | Displacement | Type of joint model | Differences [%] | Limit displacement [mm] | ||||
|---|---|---|---|---|---|---|---|---|
| Rigid | Semi-rigid | Nominally pinned | ([4]/[6]-1)·100% | ([5]/[6]-1)·100% | ||||
| BOM R16 | BOM R16 | |||||||
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |
| N4 | Horizontal [mm] | 2.1 | 5.0 | 6.1 | 3.6 | 39 | 69 | 35 |
| N36 | Vertical [mm] | 27.9 | 49.8 | 53.8 | 33.9 | 47 | 56 | 96 |
Test results for specimens M16_4/4 with washers under the bolt head and nut
| Specimen | Number of washers w | (Fmax) [kN] | δ (Fmax) [mm] | Bearing factor acc. to test Fmax/2fudt | Bearing factor acc. to EC3 [10] k 1 αb | Characteristic bearing resistance acc. to EC3 [10] 2Fb,Rk = 2k 1 αb fudt[kN] | [Fmax /(2Fb,RK )]·100% |
|---|---|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
| M16.4/4-1 | 4 | 120.01) | 12.0 | - | 2.31 | 107.2 | 112 |
| M16.4/4-2 | 122.41) | 11.5 | - | 114 | |||
| M16.4/4-3 | 142.52) | 9.1 | - | 133 |
Initial stiffness of connections in tested specimens
| Specimen | Initial stiffness [kN/mm] |
|---|---|
| 1 | 2 |
| M16.4 | 14.11) |
| BOM-S.4 | 27.92) |
| BOM-KSW.4 | 40.92) |
Test results for specimens M16_4/2 with washers under the nut only
| Specimen | Number of washers w | (Fmax) [kN] | δ (Fmax) [mm] | Bearing factor acc. to test Fmax/2fudt | Bearing factor acc. to EC3 [10] k 1 αb | Characteristic bearing resistance acc. to EC3 [10] 2Fb,Rk = 2k 1 αb fudt[kN] | Fmax /(2Fb,RK )]·100% |
|---|---|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
| M16.4/2-1 | 2 | 108.2 | 15.4 | 2.33 | 2.31 | 107.2 | 101 |
| M16.4/2-2 | 107.9 | 17.1 | 2.33 | 100 | |||
| M16.4/2-3 | 110.2 | 16.7 | 2.37 | 103 | |||
| M16.4/2-4 | 109.6 | 16.3 | 2.36 | 102 | |||
| M16.4/2-5 | 114.1 | 19.0 | 2.46 | 106 |
Parameters of specimens with M16 bolts and BOM R16-4 fasteners
| Specimen | Type | d [mm] | d 0 [mm] | e 1/d 0 | p 1/d 0 | A [mm2] | t [mm] | Steel grade | fy [MPa] | fu [MPa] | fudt [kN] |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 |
| M16.4 | M16x35-8.8 | 16.0 | 18.0 | 2.78 | 5.56 | 157 | 3.69 | S235 | 283 | 393 | 23.2 |
| B0M-S.4 | BOM R16-4 | 13.6 | 14.3 | 3.50 | 6.99 | 161 * | 4.06 | S235 | 260 | 343 | 19.9 * |
| B0M-KSW.4 | BOM R16-4 | 13.6 | 14.0 | 3.57 | 7.14 | 154 * | 4.00 | S355 | 362 | 522 | 29.2 * |