SWEDISH COLLEGE OF ENGINEERING & TECHNOLOGY

Engr.Muhammad Abbas Qurshi

SWEDISH COLLEGE OF ENGINEERING & TECHNOLOGY

Strength of Materials-ICE-207(2+1)


Course Content• Stress & Strain• Statically determinate & Indeterminate Compatibility

problems ,compound bars• Shear force & Bending Moment Diagrams• Application of Stress & Strain• Bending in Beam• Stresses in Beam• Deflection in Beam• Principal of superposition• Relation between load, shear force, bending moment


Course Content• Distribution of shear stresses in beam of symmetrical section• Theory of bending• Deflection of beam using double integration, Moment area

and conjugate beam method• Combined bending & direct stress• Torsion of circular section

Recommended BookStrength of Materials• Andrew Pytel• Ferdinand L. Singer


Instruction

• Bring Text book in every class• Bring Calculator with you• 5 min max. tolerance in timing• 75% Attendance is mandatory no exception• Submit Assignment in time to Class

Representative.


ENGINEERING MECHANICS

STATICS DYNAMICS MECHANICS OF SOLIDS


• Static• Dynamic

• Strength of Materials

Study of External Effects on Rigid body

Study of internal affects


DIFFERENT NAME OF SUBJECT

Strength of Materials

Mechanics of Materials

Mechanic of Deformable bodies

Mechanics of Solids


• All branches of Engineering deal with physical systems, the component parts of which are to be assigned definite physical sizes, fabricated from some materials.


• Appropriate sizing is necessary for these part to safely withstand the imposed forces on them and at optimal cost. (Design)


• It is essential to study the behavior of the material from strength and deformation point of view as well as characteristics of different kind of forces, which cause different type of stresses in the material.


Definition

• The subject that deals with the analytical determination of strength , deformation characteristics(Stiffness) and stability of different members is designated as “Strength of Materials”

• Strength • Stiffness• Stability


Units

SI units• The basic units in this system are:– Metre(m) for length– Kilogram(Kg) for mass; and– Second (s) for time


Derived Units

• Area (m2)• Velocity (m/s)• Acceleration (m/s2)• Force (kg. m/s2 Newton. N) • Stress (Force/Unit Area)

P/A = N/m2 Pa (Pascal)Kpa=103 Pa Mpa =106 pa1N/mm2 106 N/m2 (106 Pa)


Forces

Body ForceThe body force act throughout the body andassociated with the units of volume of body.(Distributed over the volume of system but when

we analyze we say it acts through the center of gravity)– Gravitational force– Inertial force – Magnetic force


Surface Force

• The surface force act on the surface or area elements of the body.(Could be concentrated force or distributed force)– Surface traction (act on boundary)


Internal Force

• To know internal force we must know the concept of freebody diagramFree body diagram can be of section or complete member– Idealized line diagram– Applied forces– Reaction at section


Stress

Stress is the expression of force applied to a unit area of surface. It is measured in psi (English unit) or in MPa (SI unit).

stress = force / area


Simple Stresses

• There are three types of simple stress namely; normal stress, shearing stress, and bearing stress.

Normal Stress

• The resisting area is perpendicular to the applied force, thus normal. There are two types of normal stresses;– tensile stress and – compressive stress. Tensile stress applied to bar tends the bar to elongate whilecompressive stress tend to shorten the bar.

б =P/Awhere

P is the applied normal load A is the area



Dividing the load by area does not give the stress at all points in the cross-sectional area; it merely determines the average stress.A more precise definition of Stress is obtained by dividing the differential load by the differential area over which it acts:

б= dP/dA


QUESTIONS

1. What are the units of ‘Force' and ‘Stress’ in both systems?.

2. What is the definition of ‘Normal Stress’?.3. What is meant by ‘free-body diagram’?.4. What are different name of subject?.5. Why we study this subject?.

SWEDISH COLLEGE OF ENGINEERING & TECHNOLOGY

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