Exam 2 Solution - P1 - Purdue University · 2020. 10. 28. · Please use the coordinate system already provided in the figures. The centroid and the area moment of inertia are shown

SOLUTION

Problem 1.

A structural ‘T’ section is used as a cantilever beam (AC) to support a distributed load of 1 kip/ft and a point load of 50 kips as shown in Fig. 1.

(a) Draw the Shear Force and Bending Moment Diagrams for the beam (b) Determine the location (x,y) and magnitude of maximum Tensile Flexural stress. (c) Determine the location (x,y) and magnitude of maximum Compressive Flexural stress.

Please use the coordinate system already provided in the figures. The centroid and the area moment of inertia are shown in the figure.

Fig. 1

SOLUTION

Solution:

(a) ShearForceandBendingMomentDiagrams:

FromtheBendingMomentDiagram,itcanbeobservedthatthereisapositivemaximumandnegativemaximummoment.Thecrosssectionisunsymmetrical,thereforeboththepoints(! = 144 !". !"# ! =192 !".)ofmaximummomentneedtobeinvestigated.Atx=144in,y=-12in,M=-864kipsin.

! = − −864 −122700 = −3.84 !". (!)

Atx=144in,y=6in,M=-864kipsin.

! = − −864 62700 = 1.92 !"# (!)

Atx=192in,y=-12in,M=960kipsin.

! = − 960 −122700 = 4.26!"# (!)

Atx=192in,y=6in,M=960kipsin.

! = − 960 62700 = −2.13 !"# (!)

(b) LocationofmaximumCompressiveStress:x=144in.,y=-12in.

MagnitudeofmaximumCompressivestress:3.84ksi

(c) LocationofmaximumTensileStress:x=192in.,y=-12in.

MagnitudeofmaximumTensilestress:4.26ksi

SOLUTION

SOLUTION

SOLUTION

For determinant beams, internal reactions are found directly from equilibrium analysis. Equilibrium is not material dependent.

SOLUTION