A strut in a steel truss is composed of two equal angles ISA, 150 mm x 150 mm of thickness 10 mm connected back to back to the same side of a gusset plate.
The cross-sectional area of each angle is
$2921 m m^{2}$
moment of inertia
$(I_{x x} = I_{y y}) = 6335000 m m^{4}$
The distance of the centroid of the angle from its surface
$(C_{x} = C_{y}) = 40.8 m m$
The minimum radius of gyration of the strut is ___.

29.8 mm

No worries! We‘ve got your back. Try BYJU‘S free classes today!

93.2 mm

No worries! We‘ve got your back. Try BYJU‘S free classes today!

46.6 mm

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

62.7 mm

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Open in App

Solution

The correct option is C 46.6 mm
Area of each angle
$A_{1} = 2921 m m^{2}$

Min radius of gyration of structure

$r_{m i n} = \sqrt{\frac{I_{m i n, s t r u t}}{A_{s t r u t}}} = \sqrt{\frac{2 I_{x x}}{2 A_{1}}}$

$= \sqrt{\frac{6335000}{2921}}$

= 46.6 mm

Suggest Corrections

Similar questions

Q. A strut member used in a roof truss consisting of equal angles of ISA 100 mm x 100mm x 10 mm thick are placed on either sides of 16mm thick gusset plate. The cross sectional area of angle section is 1903 mm

^{2}

and Moment of inertia is

I_{x x} = I_{y y} = 177 \times 10^{4} m m^{4}

then the minimum radius of gyration is ______.

Q. A 12 mm thick angle member is connected to a 16 mm thick gusset plate as a strut in a roof truss. Minimum and maximum strength of fillet weld is ensured respectively.The minimum size of fillet weld is_____ mm and maximum size of fillet weld is______ mm.

Q. Two equal angles ISA 100 mm x 100 mm of thickness 10 mm are placed back-to-back and connected to the either side of a gusset plate through a single row of 16 mm diameter rivets in double shear. The effective area of the connected and unconnected legs of each of these angles are 775 mm

^{2}

and 950 mm

^{2}

, respectively. If these angles are not tack riveted, the net effective area of this pair of angles is______.

An unequal angle section $200 mm \times 150 mm \times 15 mm$ is to be used in a truss as a strut of effective length 4.5 m. The cross - sectional properties of the section are as follows:
$Area of cross - section = 5025 m m^{2}$
$I_{x x} = 2 \times 10^{7} m m^{4}, I_{y y} = 9.7 \times 10^{6} m m^{4}$ $a n d I_{x y} = - 8.3 \times 10^{6} m m^{4}$

By using the table of permissible compressive stress given below, the load on the member should be_____kN
$\begin{matrix} λ & 100 & 110 & 120 & 140 & 150 & 160 & 170 & 180 σ_{a c} (M P a) & 80 & 72 & 64 & 51 & 45 & 41 & 37 & 33 \end{matrix}$

Q. A truss tie consisting of 2 ISA 75 x 75 x 8 mm carries a pull of 150 kN. At ends the two angles are connected, one each on either side of a 10 mm thick gusset plate, by 18 mm diameter rivets arranged in one row. The allowable stresses in rivet are

f_{s}

= 90.0 N/

m m^{2} a n d f_{b r}

= 250 N/

m m^{2}

.

Minimum number of rivets required at each end is ________.

Join BYJU'S Learning Program

The correct option is C 46.6 mmArea of each angle A1=2921mm2 Min radius of gyration of structure rmin=√Imin,strutAstrut=√2Ixx2A1 =√63350002921 = 46.6 mm

The correct option is C 46.6 mm
Area of each angle
$A_{1} = 2921 m m^{2}$

Min radius of gyration of structure

$r_{m i n} = \sqrt{\frac{I_{m i n, s t r u t}}{A_{s t r u t}}} = \sqrt{\frac{2 I_{x x}}{2 A_{1}}}$

$= \sqrt{\frac{6335000}{2921}}$

= 46.6 mm