BTECH CHERRY FILE (STRUCTURAL TERMS)

MAGNITUDE

the amount of force, N

DIRECTION

refers to the orientation of its path or line of action. It is usually described

by the angle that the line of action makes with some reference.

SENSE

refers to the manner in which it acts along its line of action

COPLANAR

all acting in a single plane of a vertical wall

PARALLEL

all having the same direction

CONCURRENT

all having their lines of action intersect at a common point.

MOMENT

force x distance

CENTER OF MOMENT

moment can be about any point called

MOMENT ARM

distance from center of moment to force

shortest or perpendicular distance from the center of moment to line of

action of force.

CONCENTRATED LOADS

example is a beam supporting a column

UNIFORM LOADS

a series of uniform concentrated loads, but for 5 or

more uniformly spaced concentrated loads.

OTHER LOADS

varying load, moment load

TYPES OF SUPPORT

HINGED

ROLLER

FIXED/ RESTRAINED

TENSION

pulls away from joint

COMPRESSION

pushes towards joint

SHEAR

for connections

AMERICAN SOCIETY FOR TESTING AND MATERIALS

ASTM

AMERICAN CONCRETE INSTITUTE

ACI

0.003

According to ACI code, I the strain in concrete reaches ____ It begins to crack

AMERICAN INSTITUTE FOR STEEL CONSTRUCTION

AISC

0.0021

If a grade 60 steel (fy= 60ksi= 414Mpa) reaches a strain _____ it begins to

yield of (2.1mm)

STRESS- STRAIN DIAGRAM

a graphic representation of the relationship between unit stress values and the

corresponding unit strains for a specific material

PROPORTIONAL LIMIT

maximum stress which the material springs back to the original length when

the load is released

ELASTIC LIMIT

maximum stress below which the material does not return to its original

length but has incurred a permanent deformation we call permanent set

ULTIMATE STRENGTH

the maximum stress that can be attained immediately before actual failure or

rupture

RUPTURE STRENGTH

stress at which material specimen breaks

ALLOWABLE STRESS

the maximum unit stress permitted for a material in the design of a structural member,

usually a fraction of the material’s elastic limit, yield strength, or ultimate strength.

Also called ALLOWABLE UNIT STRESS, WORKING STRESS.

ELASTIC RANGE

the range of unit stresses for which a material exhibits elastic deformation

ELASTIC DEFORMATION

a temporary change in the dimensions or shape of a body produced by a stress less

than the elastic limit of the material

BRITLENESS

the property of material that causes it to rupture suddenly under stress with little evident

deformation. Since brittle materials lack the plastic behavior of ductile materials, they

can give no warning of impending material

YIELD POINT

the stress wherein the deformation increases without any increase in the load.

The material at some portion shows a decrease in its cross section

DUCTILITY

the property of a material that enables it to undergo plastic deformation after being

stressed beyond the elastic limit and before rupturing.

ELASTICITY

the property of a material that enables it to deform in response to an applied force and

to recover its original size and shape upon removal of the force

MALLEABILITY

the ability of a material to regain and rebound to original shape when the load is

released

TOUGHNESS

the property of a material that enables it to absorb energy before rupturing, represented

by the area under the stress- strain curve derived from a tensile test of the material.

Ductile materials are tougher than brittle materials.

MODULUS OF ELASTICITY

a coefficient of elasticity of a material expressing the ratio between a unit stress aSd the

corresponding unit strain caused by the stress, as derived from Hooke’s law and

represented by the slope of he straight line portion of the stress- strain line diagram.

Also called COEFFICIENT OF ELASTICITY, ELASTIC MODULUS

PERMANENT SET

the inelastic strain remaining in a material after complete release of the stress producing

deformation

YIELD STRENGTH

the stress necessary to produce a specific limiting permanent set in a material,

usually 0.2% of its original length when tested in tension. _______- is used to

determine the limit of usefulness of a material having a poorly defined yield point.

Also called POOR STRESS.

STRAIN- RATE EFFECT

the behavior an increased rate of load application can cause in normally ductile material

TEMPERATURE EFFECT

the brittle behavior low temperatures can cause in a normally ductile material

STRESS RELAXATION

the time- dependent decrease in stress in a constrained material under a constant load

CREEP

the gradual permanent deformation of a body produced by a continued application of

stress or prolonged exposure to heat. _____deflection in a concrete structure continues

over time and can be significantly grater than the initial elastic deflection

FATIGUE

the weakening or failure of a material at a stress below the elastic limit when subjected

to a repeated series of stresses

14.5 ksi

Maximum allowable stress (Fv) in shear is

24 ksi

Maximum allowable stress (Fb) for bending is

29,000 ksi

Modulus of elasticity (E) is

TENSION

the act of stretching or state of being pulled apart, resulting in the elongation of an

elastic body

TENSILE FORCE

an applied force producing or tending to produce tension in an elastic body

AXIAL FORCE

a tensile or compressive force acting along the longitudinal axis of a structural member

and at the centroid of the cross section, producing ______stress without bending, torsion

or shear also called _________

AXIAL STRESS

the tensile or compressive stress that develops to resist axial force, assumed to be

normal to and uniformly distributed over the area of the cross section.

Also called DIRECT STRESS, NORMAL TRESS

COMPRESSION

the act of shortening or state of being pushed together, resulting in the reduction in size

or volume of an elastic body

COMPRESSIVE FORCE

an applied force producing or tending to produce compression in an elastic body

ECCENTRIC FORCE

force applied parallel to the longitudinal axis of a structural member but not to the

centroid of he cross section, producing bending and uneven distribution of stresses in

the section.

STRESS-

the internal resistance or reaction of an elastic body to external forces applied to it.

Equal to the ratio of force to area and expressed in units of force per unit of cross-

sectional area.

TENSILE STRESS

the axial stress that develops at the cross section of an elastic body to resist the

collinear tensile forces tending to elongate it.

TENSILE STRAIN

the elongation of a unit length of material produces by a tensile stress

ELONGATION

a measure of ductility of a material, expressed as the percentage increase in length of a

test specimen after failure in tensile test

REDUCTION OF AREA

a measure of ductility of a material, expressed as the percentage decrease in cross-

sectional area of a test specimen after rupturing in a tensile test

TENSILE STRENGTH

the resistance of a material to longitudinal stress, measured by the minimum amount of

longitudinal stress required to rupture the material

STRAIN

the deformation of a body under the action of an applied force. _____ is a dimensionless

quantity, equal to the ratio of the change in size and shape to the original size and

shape of a stressed element.

STRAIN GAUGE /EXTENSOMETER

an instrument for measuring minute deformation in a test specimen caused by tension,

compression, bending or twisting.

YOUNG’S MODULUS

a coefficient of elasticity of material expressing the ratio of longitudinal stress to the

corresponding longitudinal strain caused by the strain.

POISSON’S RATIO

the ratio of lateral strain to the corresponding longitudinal strain in an elastic body under

longitudinal stress

COMPRESSIVE STRESS

the axial stress that develops at the cross section of an elastic body to resist the

collinear compressive forces tending to shorten it.

COMPRESSIVE STRAIN

the shortening of a unit length of material produced by a compressive stress

SHEAR

the lateral deformation produced in a body by an external force that causes one part of

the body to slide relative to an adjacent part in a direction parallel to their plane contact.

SHEAR FORCE

an applied force producing or tending to produce shear in the body

SHEARING FORCE

an internal force tangenial to the surface on which it acts, developed by a body in

response to shear, shearing in a vertical plane necessarily involves shearing in a

horizontal plane and vise versa

SHEARING STRESS

the force per unit area developed along a section of an elastic body to resist a shear

force.

SHEARING STRAIN

the lateral deformation developed in a body in response to shearing stresses, defined as

the tangent of the skew angle of the deformation.

SHEAR MODULUS OF ELASTICITY

a coefficient elasticity of a material, expressing the ratio between shearing stress and

the corresponding shearing strain produced by the strain.

BENDING

the bowing of an elastic body as an external force is applied transversely to its length. ________is the structural mechanism that enables a load to be mechanism that enables a load to be channeled in a direction perpendicular to its application.

TRANSVERSE FORCE

a force applied perpendicular to the length of a structural member, producing bending and shear

TORQUE

the moment of a force system that causes or tends to cause rotation or torsion

TORSION

the twisting of an elastic body about its longitudinal axis caused by two equal and opposite torques, producing shearing stresses in the body

EFFECTIVE LENGTH

the depth of concrete section measured from the compression face to the centroid of the tension reinforcement

COVER

the amount of concrete required to protect steel reinforcement from fire and corrosion, measured from the surface of the reinforcement to outer surface of the concrete section

BOND STRESS

the adhesive for per unit area of contact between reinforcing bar and the surrounding concrete developed at any section of a flexural member

HOOK

a bend or curve given to develop an equivalent embedment length, used where there is insufficient room to develop in adequate embedment length

STANDARD HOOK

a 90º, 135º, 180º bend made at the end of a reinforcing bar according to standards

ANCHORAGE

any of various means, as embedment length or hooked bars, for developing tension or compression in a reinforcing bar on each side of critical section in order to prevent bond failure or splitting

CRITICAL SECTION

the section of a flexural concrete member at a point of maximum stress, a point of inflection, or appoint within the span where tension bars are no longer needed to resist stress

BALANCED SECTION

a concrete in which the tension reinforcement theoretically reaches its specified yield strength as the concrete in compression reaches its assumed ultimate strain

OVERREINFORCED SECTION

a concrete section in which the concrete in compression reaches its assumed ultimate strain before the tension reinforcement reaches its specified yield strength. This is a dangerous condition since failure of the section could occur instantaneously without warning

UNDERREINFORCED SECTION

a concrete section in which the tension reinforcement reaches its specified yield strength before the concrete in compression reaches its assumed ultimate strain. This is desirable condition since failure of the section would be preceded by large deformations giving prior warning of impending collapse

BEAM

a rigid structural member designed to carry and transfer transverse loads across spaces supporting elements

SPAN

the extent of space between two supports of a structure

CLEAR SPAN

the distance between inner faces of the support of a span

BENDING MOMENT

an external moment tending to cause part a structure to rotate or bend, equal to the algebraic sum of the moments about the neutral axis of the section under consideration

RESISTING MOMENT

an internal moment equal and opposite to a bending moment, generated by a force couple to maintain equilibrium of the section being considered

DEFLECTION

the perpendicular distance a spanning member deviates from a true course under transverse loading, increasing with load and span, and decreasing with an increase in the moment of inertia of the section of the modulus of elasticity of the material

NEUTRAL AXIS

an imaginary line passing through the centroid of the cross section of a beam, other member subject to bending, along which no bending stresses occur

BENDING STRESS

a combination of compressive and tensile stresses developed at a cross section of structural member to resist transverse force, having a maximum value at the surface furthest from the neutral axis

CAMBER

a slight convex curvature intentionally built into beam, girder, or truss to compensate for an anticipated deflection

TRANSVERSE SHEAR

an external shear force at a cross section of a beam or other member subject to bending, equal to the algebraic sum of transverse forces on one side of the section

VERTICAL SHEARING

the shearing stress developed along cross section of a beam to resist transverse shear,

having a maximum value at the neutral axis and decreasing nonlinearly toward the outer

faces

HORIZONTAL SHEARING

the shearing stress developed to prevent slippage along longitudinal planes of a beam

under transverse loading, equal to any point to the vertical shearing stress at that point.

Also called LONGITUDINAL SHEARING STRESS

FLEXURE FORMULA

a formula defining the relationship between bending moment, bending stress, and the

cross sectional properties of a beam. Bending stress is directly proportional to bending

moment and inversely proportional to the moment of inertia of a beam section.

MOMENT OF INERTIA

the sum of the products of each element of an area and the square of its distance from a

coplanar axis of rotation._________ is a geometric property that indicates how

the cross sectional area of structural member is distributed and does not reflect the

intrinsic physical properties of a material