STRUCTURAL ANALYSIS

Structural Analysis- the prediction of the

performance of a given structure under prescribed loads and/or other external effects, such as support movement and temperature changes.

Common Performance Characteristics in Design of Structures:(1)Stresses or Stress Resultant

- axial forces, shear forces, bending moments

(2) Deflections(3) Support Reactions

HISTORICAL BACKGROUND

- Dawn of History : structures were designed by trial and error using rule of thumb based on past experience

- Mid 17th Century : engineers began applying Mechanics (Math and Science) in designing structures

Some of the Magnificent Structures from Earlier Eras Still Existing

- Egyptian Pyramids (about 300 BC)- Greek Temples (500 – 200 BC)- Roman Coliseum and Aqueducts (200BC – AD200)- Gothic Cathedrals (AD100 – 1500)

Galileo Galilei- considered as the originator of the theory of

structuresThe book: Two New Sciences-published in 1638, discussed the analysis on

the failure of simple structures including cantilever beams and the approximate predictions on the strength of beams

- ushered a new era of structural engineering in which analytical principles of mechanics and strength of materials would have major influence on the design of structures

- 18th Century Robert Hooke (1635-1730)

- developed the law of linear relationship between the force and the deformation of materials (Hooke’s Law)

Isaac Newton (1642 – 1727)- formulated the laws of motion and

developed calculus (foundational mechanics)

John Bernoulli (1667 – 1748)- formulated the principle of virtual work

Leonhard Euler ( 1707-1783)- developed the theory of buckling

columns

C. de Coulomb (1736-1806)- presented the analysis of elastic bending

of beams

1800’s L.M. Navier (1785-1836)

- published a treatise on elastic behavior of structures (1st textbook on modern theory of strength of materials) in 1826.

B.P. Clapeyron (1799 – 1864)- formulated the three-moment equation

for the analysis of continuous beams

J.C. Maxwell (1831-1879)- presented the method of consistent

deformations and the law of reciprocal deflections

Otto Mohr (1835 – 1918)- developed the conjugate beam method

for calculation of deflection and Mohr’s circle of stress and strain

Alberto Castigliano (1847 – 1884)- formulated the theorem of least work

C.E. Greene (1842 – 1903)- developed the area moment method

H. Muller-Breslau (1851 – 19250- presented a principle for constructing an

influence line

G.A. Maney (1888 -1947)- developed the slope deflection method (the precursor

of matrix stiffness method)

Hardy Cross (1885 – 1959)- developed the moment distribution method in 1924

(most widely used by structural engineers between 1930 to 1970)

- provided significant understanding on the behavior of statically indeterminate frames

- design of high rise buildings and other huge structures would not have been possible without the moment distribution method of analysis

1950’s-development of the revolutionized

structural analysis using computers- computers could solve large systems of

simultaneous equations that was usually performed in weeks but now in seconds

Contributors on the current computer method on structural analysis:

- J.H. Argyris - R.K. Livesley- R.W. Clough - H.C. Martin- S. Kelsey - M.T. Turner- E.L. Wilson - O.C. Zienkiewicz

Structural Engineering- the science and art of planning, designing

and constructing safe and economical structures that will serve their intended purposes

Note: Structural Analysis is an integral part of any structural engineering project, its function being the prediction of the performance of the proposed structure.

ESTIMATION OF LOADS

PRELIMINARY STRUCTURAL DESIGN

STRUCTURAL ANALYSIS

PLANNING PHASE

Are the safety and

serviceability satisfied?

Revise Structural

Design

NO

YES

RECONSTRUCTION PHASE

PHASE OF A TYPICAL STRUCTURAL ENGINEERING PROJECT

CLASSIFICATION OF STRUCTURES