# Questions & Answers of Steel Structures

#### Topics of Steel Structures 42 Question(s) | Weightage 05 (Marks)

A steel column of ISHB 350 @72.4 kg/m is subjected to a factored axial compressive load of 2000 kN. The load is transferred to a concrete pedestal of grade M20 through a square base plate. Consider bearing strength of concrete as $0.45f_{ck}$, where $f_{ck}$ is the characteristic strength of concrete. Using limit state method and neglecting the self weight of base plate and steel column, the length of a side of the base plate to be provided is

In a fillet weld, the direct shear stress and bending tensile stress are 50 MPa and 150 MPa, respectively. As per Is 800: 2007, the equivalent stress (in MPa, up to two decimal places) will be ______

The dimensions of a symmetrical welded I-section are shown in the figure.

The plastic section modulus about the weaker axis (in cm3, up to one decimal place) is ______

A fillet weld is simultaneously subjected to factored normal and shear stresses of 120 MPa and 50 MPa, respectively. As per IS 800 : 2007, the equivalent stress (in MPa, up to two decimal places) is ______

Four bolts P, Q, R and S of equal diameter are used for a bracket subjected to a load of 130 kN as shown in the figure.

The force in bolt P is

A prismatic propped cantilever beam of span $L$ and plastic moment capacity $M_p$ is subjected to a concentrated load at its mid-span. If the collapse load of the beam is $\alpha\frac{M_p}L$ , the value of $\alpha$ is ______

A column is subjected to a load through a bracket as shown in the figure.

The resultant force (in kN, up to one decimal place) in the bolt 1 is ___________

Two plates of 8 mm thickness each are connected by a fillet weld of 6 mm thickness as shown in the figure.

The permissible stresses in the plate and the weld are 150 MPa and 110 MPa, respectively. Assuming the length of the weld shown in the figure to be the effective length, the permissible load P (in kN) is  ____________

The semi-compact section of a laterally unsupported steel beam has an elastic section modulus, plastic section modulus and design bending compressive stress of $500\mathrm{cm}^3$ ,$650\mathrm{cm}^3$ and, $200\;\mathrm{MPa}$ respectively. The design flexural capacity (expressed in kNm) of the section is _________

A propped cantilever of span L carries a vertical concentrated load at the mid-span. If the plastic moment capacity of the section is $M_p$, the magnitude of the collapse load is

Two plates are connected by fillet welds of size 10 mm and subjected to tension, as shown in the figure.  The thickness of each plate is 12 mm.  The yield stress and the ultimate tensile stress of steel are 250 MPa and 410 MPa, respectively.  The welding is done in the workshop $\left(\gamma_{mw}=1.25\right)$.

As per the Limit State Method of IS 800: 2007, the minimum length (rounded off to the nearest higher multiple of 5 mm) of each weld to transmit a force P equal to 270 kN (factored) is

Two bolted plates under tension with alternative arrangement of bolt holes are shown in figures 1 and 2. The hole diameter, pitch, and gauge length are d, p and g, respectively.

Which one of the following conditions must be ensured to have higher net tensile capacity of configuration shown in Figure 2 than that shown in Figure 1 ?

A fixed-end beam is subjected to a concentrated load $\left(P\right)$ as shown in the figure. The beam has two different segments having different plastic moment capacities $(M_p,\;2M_p)$ as shown.

The minimum value of load $\left(P\right)$ at which the beam would  collapse (ultimate load) is

A bracket plate connected to a column flange transmits a load of 100 kN as shown in the following figure. The maximum force for which the bolts should be designed is _____ kN.

For formation of collapse mechanism in the following figure, the minimum value of Pu is cMp/L. Mp and 3Mp denote the plastic moment capacities of beam sections as shown in this figure. The value of c is________.

Prying forces are :

A steel member ‘M’ has reversal of stress due to live loads, whereas another member ‘N’ has reversal of stress due to wind load. As per IS 800:2007, the maximum slenderness ratio permitted is:

The ultimate collapse load (P) in terms of plastic moment Mp by kinematic approach for a propped cantilever of length L with P acting at its mid-span as shown in the figure, would be

A steel section is subjected to a combination of shear and bending actions. The applied shear force is V and the shear capacity of the section is Vs. For such a section, high shear force (as per IS:800-2007) is defined as

The tension and shear force (both in kN) in each bolt of the joint, as shown below, respectively are

A prismatic beam (as shown below) has plastic moment capacity of Mp, then the collapse load P of the beam is

As per IS 800:2007, the cross-section in which the extreme fiber can reach the yield stress, but cannot develop the plastic moment of resistance due to failure by local buckling is classified as

Two steel columns P (length L and yield strength fy=250 MPa) and Q (length 2L and yield strength fy=500 MPa) have the same cross-sections and end-conditions. The ratio of buckling load of column P to that of column Q is:

A propped cantilever made of a prismatic steel beam is subjected to a concentrated load P at mid span as shown.

If load P=80 kN,find the reaction R(in kN) (correct to 1-decimal place)using elastic analysis. __________

A propped cantilever made of a prismatic steel beam is subjected to a concentrated load P at mid span as shown.

If the magnitude of load P is increased till collapse and the plastic moment carrying capacity of steel beam section is 90 kNm, determine reaction R(in kN)(correct to 1-decimal place) using plastic analysis. __________

In a steel plate with bolted connections, the rupture of the net section is a mode of failure under

Two plates are connected by fillet welds of size 10 mm and subjected to tension, as shown in the sketch. The thickness of each plate is 12 mm. The yield stress and the ultimate tensile stress of steel are 250 MPa and 410 MPa, respectively. The welding is done in the workshop (${\gamma }_{mw}$ = 1.25). As per the Limit State Method of IS 800:2007, the minimum length (rounded off to the nearest higher multiple of 5 mm) of each weld to transmit a force P equal to 270 kN is

For the fillet weld of size "s" shown in the adjoining figure the effective throat thickness is

The value of W that results in the collapse of the beam shown in the adjoining figure and having a plastic moment capacity of Mp is

The adjoining figure shows a schematic representation of a steel plate grider to be used as a simply supported beam with a concentrated load. For stiffeners, PQ(running along the beam axis) and RS(running between the top and bottom flanges) which of the following pairs of statements will be TRUE?

A double cover butt riveted joint is used to connect two flat plates of 200mm width and 14mm thickness as show in the figure. There are twelve power driven rivets of 20mm diameter at a pitch of 50mm in both directions on either side of the plate. Two cover plates of 10mm thickness are used. The capacity of the joint in tension considering bearing and shear ONLY, with permissible bearing and shear stresses as 300 MPa respectively is

Two plates, subjected to direct tension, each of 10 mm thickness and having widths of 100 mm and 175 mm, respectively are to be fillet welded with an overlap of 200 mm. Given that the permissible weld stress is 110 MPa and the permissible stress in steel is 150 MPa, then length of the weld required using the maximum permissible weld size as per IS:800-1984 is

In the theory of plastic bending of beams, the ratio of plastic moment to yield moment is called

The square root of the ratio of moment of inertia of the cross section to its cross sectional area is called

A 12 mm thick plate is connected to two 8 mm plates, on either side through a 16 mm diameter power driven field rivet as shown in the figure below. Assuming permissible shear stress as 90 MPa and permissible bearing stress as 270 MPa in the rivet, the rivet value of the joint is

Consider the following statements for a compression member:

I. The elastic critical stress in compression increases with decrease in slenderness ratio.
II. The effective length depends on the boundary conditions at its ends.
III. The elastic critical stress in compression is independent of the slenderness ratio.
IV. The ratio of the effective length to its radius of gyration is called as slenderness ratio.

The TRUE statements are

The shape of the cross-section, which has a largest shape factor, is

Rivets and bolts subjected to both shear stress $\left({\tau }_{\nu f,cal}\right)$ and axial tensile stress $\left({\sigma }_{tf},cal\right)$ shall be so proportioned that the stresses do not exceed the respective allowable stresses , and the value of $\left(\frac{{\tau }_{vf,cal}}{{\tau }_{vf}}+\frac{{\sigma }_{if,cal}}{{\sigma }_{if}}\right)$ does not exceed

A continuous beam is loaded as shown in the figure below. Assuming a plastic moment capacity equal to MP, the minimum load at which the beam would collapse is

A steel flat of rectangular section of size 70 × 6 mm is connected to a gusset plate by three bolts each having a shear capacity of 15 kN in holes having diameter 11.5 mm. If the allowable tensile stress in the flat is 150 MPa, the maximum tension that can be applied to the flat is