Structures II Exam 2

rigid frames

only 1 joint needs to be rigid

costlier than braced frames

point of inflection

moment = 0

structure changes shape

0.55h from bottom

pinned

vertical load in middle

roller

vertical load in middle

fixed

horizontal load from left side

neutral axis

no tension or compression

neutral axis top and bottom

top shortens, compression increases from middle to top

bottom lengthens, tension increases from middle to bottom

stress/strain graph

linear relationship between stress and strain, lost after elastic limit

shear walls: 3 primary actions

direct shear, cantilever moment resistance, horizontal sliding resistance

shear walls: 2 primary forms

planar walls and core walls

n Architects - Villa-Villa, China

2 layers because of climate conditions and extreme temperature swings

inner house layer is heated and cooled, outer house layer is not heated or cooled

rigid frame - steel system, completely hidden

wood materials, masonry on outside

Foster + Partners - View Port Pavilion, France

roof is thicker in the middle, tapers down on sides

rigid frame - steel

drainage through columns

structure not expressed - reflects context and disappears

8 skinny columns

CLARE Design, Docklands Library, Melbourne, Australia

historical dock - light structure, CLT

rigid planes and frames with inner trusses

composite system

diaphragm structure to provide support

Foster + Partners - Renault Centre, UK

modular structure with perpendicular grid

steel structure

wide openings

expressing structure

Foster + Partners - Science Research Center, Stanford University

2 main parts

shear walls in different directions

shear cores working up/down

parallel shear walls working left/right

shear walls at end

earthquake prone area

Junya Ishigami + Associates - Kanagawa Institute of Technology Plaza vs Kanagawa Institute of Technology Workshop

Plaza - hides structure, few vertical structural elements

Workshop - shows structure, many vertical structural elements

Foster + Partners - Hearst Tower, New York

diagonal grid (diagrid) similar to brace frames, provides vertical and lateral resistance

uses less steel by eliminating verticals

core shifted to back for views and natural light

two way structural grid - skylights

was in a movie

Buchanan Architecture - Mockingbird Residence, Texas

vertical structural elements, beams with connections, roof truss, decking, x bracing, shear walls, facade

Foster + Partners - Century Tower, Tokyo

eccentric brace because of lateral loads and earthquakes

part in the middle allows movement and flexibility

Foster + Partners - Bishops Gate Yard, London, England

modular shear walls

sectionally smaller in upper floors to have a lighter structure at the top

Mies van der Rohe - Crown Hall, IIT Campus, Chicago

rigid frame steel

poor interior climate because of a low level of insulation from the heat going through the steel beams

x frame method of joints order

B D A C

v frame method of joints order

B A D C E

steps for “determine mag and dir of forces in all members”

moment of a

method of joints

steps of “determine reactions and forces in each of FEM connections”

points of inflection

horizontal reactions

moment of e using moment of A

vertical reactions - moment of e

internal forces - moment of B

steps for shear wall problem

lateral load fb=mc/I

vertical load f=p/a

diagram