Quiz 1 Reviewer.docx

STRUCTURAL ELEMENTS Ties - subjected to axial tension forces only. - Cannot resist flexural stress.

Surface Structure - made from a material having a very small thickness compared to its other dimensions. - subjected to pure tension

Struts - axial compressions force only - cannot resist flexural stress

LOADS ON STRUCTURE

Brace - structural system to resist wind and earthquake Beams and Girders - primarily subjected to flexural stress - horizontal members that are primarily subjected to gravity forces Columns - subjected to compression forces - vertical members Diaphragms - flat plates - commonly used for floor and shear resisting walls

TYPES OF STRUCTURES Trusses - slender elements usually arranged in triangular fashion. Cables - flexible and carry their loads in tension. - commonly used when the span re greater than 46 m. Arches - achieves its strength in compression. Frames – composed of beams and columns that either pin or fixed - generally indeterminate from a standpoint of analysis

Dead Load - gravity loads of constant and fixed positions that act permanently on the structure - consist of weights of the structural system itself and of all other material and equipment permanently attached to the structural system. Live Load - varying magnitudes and/or positions caused by the use of the structure. - all loads on the structure that are not dead loads. Impact load – applied rapidly on the structure (NSCP 2010 – Section 206)  Impact – increase in stress in the structure. Environmental Load  Wind Load - loads produced by flow of wind around the structure (NSCP 2010 – Section 207)  Earthquake Load – sudden undulation of a portion of the Earth’s surface

Hydrostatic and Soil Pressure – acts normal to the submerged surface of the structure, magnitude varying linearly w/ weight. (NSCP 2010 Section 209 – 211) Load Combinations – all loads that may act simultaneously. (NSCP 2010 Section 203)

IDEALIZED STRUCTURE Support Connections - structural members are joined together. - pin connection, roller support and fixed joint. Torsional spring constant k = 0, the join is pin K = ∞, joint is fixed Line Diagram - analytical model of 2 or 3-dimensional body selected for analysis - each member of structure is represented by a line coinciding with its centroidal axis. Plane vs Space Structure – all the members of a structure as well as applied loads lie in a single plane. Tributary loadings – determine how the loads on these surfaces is transmitted to the various structural elements used for their support. 

One Way Slab – delivers its load to the supporting members by 1-way action.

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Two Way Slab – delivered the supporting beams and girders in 2 directions.

Structural Analysis 

Linear Static Analysis - linear relation holds between applied forces and displacements. - model’s stiffness matrix is constant

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Nonlinear Analysis – nonlinear relation holds between applied forces and displacements  Geometric Nonlinearity – changes in Geometry as the structure deforms  Material Nonlinearity – involves nonlinear behavior of a material based on current deformation etc...  Constraint and Contact Nonlinearity - if kinematic constraints are present in the model.