two what is the scale? what is the size in a particular direction? - PowerPoint PPT Presentation

A RCHITECTURAL S TRUCTURES : Structural Math F ORM, B EHAVIOR, AND D ESIGN • quantify environmental loads ARCH 331 D R. A NNE N ICHOLS – how big is it? S UMMER 2018 • evaluate geometry and angles lecture – where is it? two – what is the scale? – what is the size in a particular direction? • quantify what happens in the structure forces and – how big are the internal forces? – how big should the beam be? moments Forces & Moments 1 Architectural Structures F2009abn Structural Planning 32 Foundations Structures F2008abn Lecture 3 ARCH 331 Lecture 3 ARCH 331 Structural Math Physics for Structures • physics takes observable phenomena • measures and relates the measurement with rules: – US customary & SI mathematical relationships • need Units US SI Length in, ft, mi mm, cm, m – reference frame Volume gallon liter – measure of length, mass, time, direction, Mass lb mass g, kg velocity, acceleration, work, heat, Force lb force N, kN electricity, light Temperature F C – calculations & geometry Structural Planning 34 Foundations Structures F2008abn Structural Planning 33 Foundations Structures F2008abn Lecture 3 ARCH 331 Lecture 3 ARCH 331 1

Physics for Structures Language • scalars – any quantity • symbols for operations: +,-, /, x • symbols for relationships: (), =, <, > • vectors - quantities with direction • algorithms   – like displacements 2 5 2 2 1     – cancellation    – summation results in 5 6 6 2 3 3 – factors the “ straight line path ” x 1 6  – signs from start to end 3 – ratios and proportions y 10 3  – normal vector is perpendicular to – power of a number 1000 something – conversions, ex. 1X = 10 Y 10 Y 1 X  or 1 – operations on both sides of equality z 1 X 10 Y x Structural Planning 35 Foundations Structures F2008abn Structural Planning 36 Foundations Structures F2008abn Lecture 3 ARCH 331 Lecture 3 ARCH 331 On-line Practice Geometry • eCampus / Study Aids • angles – right = 90º – acute < 90º – obtuse > 90º –  = 180º • triangles B b  h  – area 2 A C – hypotenuse   2 2 2 AB AC BC – total of angles = 180º Structural Planning 37 Architectural Structures F2008abn Structural Planning 38 Foundations Structures F2008abn Lecture 3 ARCH 331 Lecture 3 ARCH 331 2

Geometry Geometry • lines and relation to angles – intersection of a line with    parallel lines results in identical  – parallel lines can ’ t intersect   angles   – perpendicular lines cross at 90º – two lines intersect in the same – intersection of two lines is a point way, the angles are identical – opposite angles are equal when    two lines cross     Structural Planning 39 Foundations Structures F2008abn Structural Planning 40 Foundations Structures F2008abn Lecture 3 ARCH 331 Lecture 3 ARCH 331 Geometry Geometry – sides of two angles are parallel and – sides of two angles bisect a right angle (90 ), the angles are complimentary intersect opposite way, the angles are supplementary - the sum is 180°      90      – right angle bisects a straight line, – two angles that sum to 90° are said to be remaining angles complimentary are complimentary        90   Structural Planning 41 Foundations Structures F2008abn Forces & Moments 12 Foundations Structures F2009abn Lecture 3 ARCH 331 Lecture 3 ARCH 331 3

Geometry Trigonometry – similar triangles have proportional sides • for right triangles B A AB AC BC   opposite side AB     sin sin AD AE DE hypotenuse CB  C B E C A  A adjacent side AC     D  cos cos hypotenuse CB A C   AB AC BC   opposite side AB            tan tan A B A C B C  adjacent side AC   C B SOHCAHTOA B  Structural Planning 43 Foundations Structures F2008abn Structural Planning 44 Foundations Structures F2008abn Lecture 3 ARCH 331 Lecture 3 ARCH 331 Trigonometry Trigonometry • cartesian coordinate system • for angles starting at positive x – sin is y side – origin at 0,0 Y Y 6 6 – cos is x side – coordinates 5 5 4 4 in (x,y) pairs Quadrant II Quadrant I 3 3 2 2 – x & y have sin<0 for 180-360° 1 1 cos<0 for 90-270° 0 0 X signs X -1 -6 -5 -4 -3 -2 -1 -1 0 1 2 3 4 5 6 tan<0 for 90-180° -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 -2 -2 tan<0 for 270-360° -3 -3 Quadrant III Quadrant IV -4 -4 -5 -5 -6 -6 Structural Planning 46 Foundations Structures F2008abn Structural Planning 45 Foundations Structures F2008abn Lecture 3 ARCH 331 Lecture 3 ARCH 331 4

Trigonometry Trigonometry • cartesian coordinate system • for angles starting at positive x – origin at 0,0 – sin is y side Y Y 6 6 – coordinates – cos is x side 5 5 4 4 in (x,y) pairs Quadrant II Quadrant I 3 3 2 – x & y have 2 sin<0 for 180-360° 1 1 cos<0 for 90-270° 0 0 X signs X -6 -5 -4 -3 -2 -1 -1 0 1 2 3 4 5 6 -1 tan<0 for 90-180° -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 -2 -2 tan<0 for 270-360° -3 -3 Quadrant III Quadrant IV -4 -4 -5 -5 -6 -6 Structural Planning 46 Foundations Structures F2008abn Structural Planning 45 Foundations Structures F2008abn Lecture 3 ARCH 331 Lecture 3 ARCH 331 Trigonometry Algebra • equations (something = something) • for all triangles  C • constants – sides A, B & C are opposite B angles  ,  &   – real numbers or shown with a, b, c...  • unknown terms, variables A – LAW of SINES – names like R, F, x, y    sin sin sin   • linear equations A B C – unknown terms have no exponents • simultaneous equations – LAW of COSINES     2 2 2 A B C 2 BC cos – variable set satisfies all equations Structural Planning 47 Foundations Structures F2008abn Structural Planning 48 Foundations Structures F2008abn Lecture 3 ARCH 331 Lecture 3 ARCH 331 5

Algebra Algebra • solving one equation • solving one equations – only works with one variable – only works with one variable      – ex: – ex: 2 x 1 0 2 x 1 4 x 5     2 x 1 1 0 1 • add to both sides • subtract from both sides 2       1 2 1 2 4 5 2 x x x x x  x • divide both sides • subtract from both sides 2 1       1 5 2 x 5 5  2 2      • get x by itself on a side  • divide both sides 6 3 2 2 x x 1   2   2 2 2 • get x by itself on a side   x 3 Structural Planning 49 Foundations Structures F2008abn Structural Planning 50 Foundations Structures F2008abn Lecture 3 ARCH 331 Lecture 3 ARCH 331 Algebra Forces • solving two equation • statics – only works with two variables – physics of forces and reactions on bodies  y  2 x 3 8 and systems – ex:  y  – equilibrium (bodies at rest) 12 x 3 6 • look for term similarity • can we add or subtract to eliminate one term? • forces – something that exerts on an object:      2 x 3 y 12 x 3 y 8 6 • add • motion 14  x 14 • tension 14 x 14 • get x by itself on a side    • compression x 1 14 14 Structural Planning 51 Foundations Structures F2008abn Point Equilibrium 2 Foundations Structures F2008abn Lecture 3 ARCH 331 Lecture 4 ARCH 331 6

Force Force Characteristics • “ action of one body on another that • applied at a point affects the state of motion or rest of the • magnitude body ” – Imperial units: lb, k (kips) • Newton ’ s 3 rd law: – SI units: N (newtons), kN – for every force of action • direction there is an equal and opposite reaction along the same line (tail) (tip) http://www.physics.umd.edu Point Equilibrium 3 Foundations Structures F2008abn Point Equilibrium 4 Foundations Structures F2008abn Lecture 4 ARCH 331 Lecture 4 ARCH 331 Forces on Rigid Bodies Transmissibility • for statics, the bodies are ideally rigid • the force stays on the same line of action • can translate • truck can ’ t tell the difference and rotate • internal forces are translate rotate – in bodies = – between bodies (connections) • external forces act on bodies • only valid for EXTERNAL forces Point Equilibrium 5 Foundations Structures F2008abn Point Equilibrium 6 Foundations Structures F2008abn Lecture 4 ARCH 331 Lecture 4 ARCH 331 7

Force System Types Force System Types • collinear • coplanar Point Equilibrium 7 Foundations Structures F2008abn Point Equilibrium 8 Foundations Structures F2008abn Lecture 4 ARCH 331 Lecture 4 ARCH 331 Force System Types Adding Vectors • space • graphically – parallelogram law R • diagonal F • long for 3 or more vectors P – tip-to-tail • more convenient F R with lots of vectors P Point Equilibrium 9 Foundations Structures F2008abn Point Equilibrium 10 Foundations Structures F2008abn Lecture 4 ARCH 331 Lecture 4 ARCH 331 8