A common connection in the actual construction design is the bolt bond at the beam button, or the beam connection button uses a vertical effect of Axial force, shear force, moment M, N, Q. This article presents a practical calculation process to make a convenient spreadsheet in this structural design.
Moment causes plate’s bending to separate the two versions of the plate, the vertical force that limits this bending (pressed two copies), so in order to favor the safety, we ignore the effects of compressive force N. Consider the connection revolving around the bolt in the same, the largest traction in the outermost bolt, ignoring the effects of the bolts in the compressed domain (near the rotating center):
$$N_{bmax}=\frac{Mh_1}{2\sum{h_i^2}}$$
$h_1 $: The distance between the two outermost bolts
$h_i $: The distance from the row number-i of bolts (tensile zone) to the center of rotation
Check the tensile and cut bolt. According to TCVN 5575: 2012, when the bolt is both tensile and cutting, it will be checked separately (because the vandalism caused by scissors occurs on the actual cross section and the destruction caused by the cut on the bolt section of the bolt). The condition is:
$$N_{bmax}\leqslant [N_{bl}]=A_{bn}f_{tb}$$
$$Q\leqslant [Q]=Af_{vb}\gamma_{vb}$$
$A_ {bn} $: the actual area of a bolt (except for threaded weakness)
$f_ {tb} $: Bolts’s tensile calculation intensity
$f_ {vb} $: The computing intensity of the bolt
$A $: The raw cross section area of the bolt body (not threaded)
In close way, bolts are subject to additional traction due to the eccentric moment of the force N with the center of rotation:
$$N_{bmax}=\frac{(M+Ny)h_1}{2\sum{h_i^2}}$$
$y $: distance from the column axis to the center of rotation.
Check the bearing bolt as above
Ban Bich must have a thickness of $t_ {bb} $ large enough to transmit traction because the moment into the bolt, must be greater than the greater value of the following two values:
$$t_{bb}\approx 1,1\sqrt{\frac{g\sum{N_{max}}}{2(b_{bb}+g)f}}, t_{bb}\approx 1,1\sqrt{\frac{g\sum{N_i}}{2(b_{bb}+h_o)f}}$$
$N_i $: Traction force in a first bolt $N_i=N_{bmax}\frac{h_i}{h_1}$
$h_o $: The height of compressive area with the assumption of compressed area stress reaches the calculation intensity f
Can be calculated close as follows:
Consider the corner welding line at the winged and n villages:
$N_c=M/h_c+N/2$
$h_c $: The central distance of two columns
The welding road is bearing. Q.
Select the height of the welding line and check the welding stress stress when tolerating $n_c $ and $q $ by comparing with the $(\beta f_w)$ welding intensity.
Specific application in structural engineering here.
