STD
Cards (254)
- may be defined as a mixture of art and science, combining the engineer's judgment.
- is the process of determining the "response" of a structure due to external "actions"
- includes changes in the geometry (displacements or deformations) and/or changes in the state of stress of the structure
- are the anticipated forces or loads during the lifetime of the structure
- are established to evaluate whether an optimum has been achieved
- ensures that intended results are achieved
- the selection of the arrangement and sizes of structural elements so that the service loads may be safely carried, and displacements are within acceptable limits.
- establish functions of the structure and set criteria for arriving at an optimum design
- arrangement of the elements to serve the function in planning
- select member sizes to satisfy an objective criterion, such as least weight or cost
- structural analysis involving modeling the loads and structural framework to obtain internal forces and any desired deflection.
- structural member sizes are determined to satisfy the requirements of the structural analysis
- are all strength and serviceability requirements satisfied and is the result optimum? Compare with predetermined criteria
- repitition of any part of 1 through 7 found necessary or desirable after the evaluation. Usually, only steps 3 through 7 will be subject to iteration
- the determination of whether or not an optimum design has been achieved
- are static forces that are relatively constant for an extended time
- the dead weight of a structure includes its full weight
- permanent appliances and any fixed decoration
- are usually variable or moving loads and are usually refered to occupational forces from occupancy and intended use
- it is a condition of a structure at which it ceases to fulfill intended function
- maximum ductile strength, buckling, fatigue, fracture, overturning, sliding
- deflection, vibration, permanent deformation, cracking
- refers to a number of steels that, because of their economy and desirable mechanical properties, are suitable for load-carrying members in structures
- the customary way to specify a structural steel is to use an
- an increase in carbon content raises the yield stress but reduces ductility, making welding more difficult
- uses carbon as chief strengthening element with minimum yield stresses ranging from 220 MPa to 290 MPa
- have yield stresses from 480 MPa to 840 MPa
- in addition to carbon and manganese, these steels contain one or more alloying elements such as columbium, vanadium, chromium, silicon, copper, and nickel
- have yield stresses of 480 MPa too 690 MPa
- these steels of higher strength are obtained by heat-treating low-alloy steels
- quenching
- tempering
- is that unit tensile stress at which the stress-strain curve exhibits a well-defined increase in deformation without an increase in stress
- is the largest unit stress that the material achieves in a tension test
- is the slope of the initial straight-line portion of the stress-strain diagram and is usually taken as 200,000 MPa for design calculation for all structural steel
- is the ability of material to undergo large inelastic deformation without fracture
- is the ability of material to absorb energy and is characterized by the area under a stress-strain curve
- is the ability of steel to be welded without changing its basic mechanical properties
- is the ration of the transverse strain to the longitudinal strain, is essentially the same for all structural steels, and has a value of 0 in the elastic range
- is the ration of the shearing stress to shearing strain during the initial elastic behavior