Strength Of Materials Flashcards
STUDY OF THE INTERNAL EFFECTS OF
EXTERNAL FORCES APPLIED TO A BODY
Strength of materials
MEASUREMENT OF THE AMOUNT OF FORCE
HELD WITHIN AN BOJECT
Stress
INTERNAL RESPONSE OF AN OBJECT TO AN
EXTERNAL PRESSURE
RESISTING FORCE PER UNIT AREA
Stress
unit of Pressure, Stress,& Strength
Pascal
FORCES
ALONG
THE
LONGITUDINAL AXIS (OR LENGTH)
OF THE MATERIAL
Axial force
STRESS DEVELOPED TO RESIST
AXIAL FORCE
Axial stress
SHORTENING OR
PUSHING TOGETHER
Compression
STRETCHING OR PUSHING
APART
Tension
FORCES PERPENDICULAR TO
THE LONGITUDINAL AXIS OF A
MEMBER
Transverse force
STRESS
ACTING
PERPENDICULAR TO THE
AREA OF CONTACT
Normal stress
STRESS
ACTING
PARALLEL TO THE AREA
Shear stress
FORCES PERPENDICULAR TO
AN AREA, IN OPPOSITION TO A
FORCE ACTING IN THE OPPOSITE
DIRECTION
Shear force
FORCES PRODUCING BOTH TENSION AND
COMPRESSION ON THE CROSS-SECTION OF THE
BODY
Bending stress
A SHEAR STRESS PRODUCED WHEN A TWIST
Torsional stress
DEFORMATION OF A BODY DUE TO STRESSCANNOT EXIST WITHOUT STRESS
• HAS NO UNIT
Strain
STRAIGHT LINE FROM
ORIGIN
LIMIT WHEREIN STRESS
IS STILL PROPORTIONAL TO
STRAIN
Proportional limit(hooke’s law)
PROPORTIONALITY
CONSTANT
BETWEEN
STRESS AND STRAIN
THE SLOPE OF THE LINE
FROM
ORIGIN
TO
PROPORTIONAL LIMIT
Modulus of elasticity (young’s modulus)
LIMIT BEYOND WHICH
THE MATERIAL WILL NO
LONGER GO BACK TO ITS
ORIGINAL SHAPE WHEN
THE LOAD IS REMOVED
Elastic limit
RANGE WHEREIN THE
SHAPE IS RECOVERABLE
AND DEFORMATION IS
REVERSIBLE
ORIGIN UP TO ELASTIC
LIMIT
Elastic range
ABILITY
OF
A
MATERIAL TO ABSORB
ENERGY
WITHOUT
CREATING A PERMANENT
DISTORTION
AREA
UNDER
THE
STRESS-STRAIN
CURVE
FROM ‘O’ TO ‘E
Elastic of resilience
RANGE WHEREIN THE
DEFORMATION
IS
PERMANENT
BEYOND ELASTIC LIMIT
Plastic range
POINT AT WHICH THE
MATERIAL
WILL
HAVE
ELONGATION
WITHOUT
ANY INCREASE IN LOAD
Yield point
THE MAXIMUM STRESS
THAT CAN BE SUSTAINED
BY THE MATERIAL
Ultimate strength (tensile strength)
THE STRENGTH OF THE
MATERIAL AT FAILURE
Rapture strength (breaking strength)
ABILITY
OF
A
MATERIAL TO ABSORB
ENERGY
WITHOUT
CAUSING IT TO BREAK
ENTIRE AREA UNDER
THE STRESS-STRAIN CURVE
FROM ‘O’ TO ‘R
Modulus of toughness
ABILITY OF A DEFORMED BODY TO RETURN TO
ITS ORIGINAL SHAPE AND SIZE WHEN THE LOAD IS
REMOVED
Elasticity
ABILITY OF A BODY TO
WITHSTAND TENSILE STRESS
Ductility
ABILITY OF A BODY TO
WITHSTAND COMPRESSIVE
STRESS
Malleability
ABILITY OF A BODY TO
ABSORB ENERGY WITHOUT
BREAKING
Toughness
RATIO OF THE CHANGE IN
WIDTH TO THE CHANGE IN
LENGTH AS A RESULT OF
STRAIN
HOW
MUCH
THE
MATERIAL WILL DEFORM IN
THE LATERAL DIRECTION WHEN
STRESS IS APPLIED IN THE
LONGITUDINAL DIRECTION
Poissons ratio
THE CHANGE IN STRAIN OF MATERIAL WITH
RESPECT TO TIME
Strain rate
TEMPORARY CHANGE IN
THE SHAPE OF A
BODY,
PRODUCED BY A STRESS LESS
THAN THE ELASTIC LIMIT OF THE
MATERIAL
Elastic deformation
INELASTIC STRAIN IN A MATERIAL
Permanent set
FAILURE CAUSED BY FLUCTUATING OR REPEATED
STRESS
LEADS TO FRACTURE (PROGRESSIVE MINUTE CRACKS
THAT GROW UNDER REPEATED STRESS)
Fatigue
TIME-DEPENDENT, GRADUAL
PERMANENT
DEFORMATION
PRODUCED BY CONTINUOUS
APPLICATION OF LOADS
CONSIDERED
TOGETHER
WITH TEMPERATURE
Creep
TIME-DEPENDENT DECREASE IN STRESS UNDER
A CONSTANT STRAIN
Stresa relaxation
