eleven other beams & pinned frames Continental train platform, - - PowerPoint PPT Presentation

▶

Jan 03, 2023 216 likes •415 views

A RCHITECTURAL S TRUCTURES : F ORM, B EHAVIOR, AND D ESIGN A RCH 331 D R. A NNE N ICHOLS F ALL 2018 lecture eleven other beams & pinned frames Continental train platform, Grimshaw 1993 Pinned Frames 1 Architectural Structures F2018abn

SLIDE 1

F2018abn Pinned Frames 1 Lecture 11 Architectural Structures ARCH 331

eleven

ther beams &

pinned frames

lecture

Continental train platform, Grimshaw 1993

ARCHITECTURAL STRUCTURES: FORM, BEHAVIOR, AND DESIGN ARCH 331

DR. ANNE NICHOLS

FALL 2018

SLIDE 2

F2018abn Pinned Frames 2 Lecture 11 Architectural Structures ARCH 331

Pinned Frames

structures with at least one 3 force body
connected with pins
reactions are equal and opposite

– non-rigid – rigid

SLIDE 3

F2018abn Pinned Frames 3 Lecture 11 Architectural Structures ARCH 331

Rigid Frames

rigid frames have

no pins

frame is all one

body

typically statically

indeterminate

types

– portal – gable

SLIDE 4

F2018abn Pinned Frames 4 Lecture 11 Architectural Structures ARCH 331

Rigid Frames with PINS

frame pieces with

connecting pins

not necessarily

symmetrical

SLIDE 5

F2018abn Pinned Frames 5 Lecture 11 Architectural Structures ARCH 331

Internal Pin Connections

statically determinant

– 3 equations per body – 2 reactions per pin + support forces

A B C D G E F Ax Ay D

SLIDE 6

F2018abn Pinned Frames 6 Lecture 11 Architectural Structures ARCH 331

Arches

ancient
traditional shape to

span long distances

Packhorse Bridge, UK Roman Aquaducts Rainbow Bridge National Monument

SLIDE 7

F2018abn Pinned Frames 7 Lecture 11 Architectural Structures ARCH 331

Arches

primarily sees compression
a brick “likes an arch”

SLIDE 8

F2018abn Pinned Frames 8 Lecture 11 Architectural Structures ARCH 331

Arches

behavior

– thrust related to height to width

SLIDE 9

F2018abn Pinned Frames 9 Lecture 11 Architectural Structures ARCH 331

Three-Hinged Arch

statically determinant

– 2 bodies, 6 equilibrium equations – 4 support, 2 pin reactions (= 6)

SLIDE 10

F2018abn

statically determinant when

– 3 equilibrium equations per link => – total of support & pin reactions (properly constrained)

zero moment at pins

Pinned Frames 10 Lecture 11 Architectural Structures ARCH 331

F1 F2 F1 F2 not independent

Compound Beams

R1x R1y MR1 R3 (internal) pin R2y R2y R2x R2x

SLIDE 11

F2018abn Pinned Frames 11 Lecture 11 Architectural Structures ARCH 331

Procedure

solve for all support forces you can
draw a FBD of each member

– pins are integral with member – pins with loads should belong to 3+ force bodies – pin forces are equal and opposite on connecting bodies – identify 2 force bodies vs. 3+ force bodies – use all equilibrium equations

SLIDE 12

F2018abn Pinned Frames 12 Lecture 11 Architectural Structures ARCH 331

Rigid Body Types

two force bodies

– forces in line, equal and opposite

three force bodies

– concurrent or parallel forces

two

A F2 B F1 a

three three

F2 A F1 B C F3 d1 d2 F2 A F1 B C F3 a

SLIDE 13

F2018abn Pinned Frames 13 Lecture 11 Architectural Structures ARCH 331

Continuous Beams

statically indeterminate
reduced moments than simple beam

SLIDE 14

F2018abn Pinned Frames 14 Lecture 11 Architectural Structures ARCH 331

Continuous Beams

loading pattern affects

– moments & deflection

max

SLIDE 15

F2018abn

max

Pinned Frames 15 Lecture 11 Architectural Structures ARCH 331

Continuous Beams

unload end span

SLIDE 16

F2018abn Pinned Frames 16 Lecture 11 Architectural Structures ARCH 331

Continuous Beams

unload middle span

max

SLIDE 17

F2018abn Pinned Frames 17 Lecture 11 Architectural Structures ARCH 331

Analysis Methods

Approximate Methods

– location of inflection points

Force Method

– forces are unknowns

Displacement Method

– displacements are unknowns

SLIDE 18

F2018abn Pinned Frames 18 Lecture 11 Architectural Structures ARCH 331

Two Span Beams & Charts

equal spans & symmetrical loading
middle support as flat slope