Structural Engg_Lec_2_Presentation_1.ppt
- 2. Structure Engineering Course Outline 7th Semester 2012-2013
- 3. Objectives • This Course aims at teaching the students the concept of analyzing indeterminate structure using classical and up to date methods. • It provides students with an understanding of the methods of analyzing indeterminate structure: – The force method of analysis • Flexibility Method – The Displacement method • Stiffness Method (An Introduction to The Finite Element Method)
- 6. Syllabus • Force Method of Analysis (flexibility method of analysis ) – Beams – Frames – Trusses • Stiffness Methods of Analysis (Displacement Method of Analysis) – Beams – Frames – Trusses
- 7. Syllabus • Introduction of dynamics • Introduction to bridge Engineering
- 8. Course Materials • Lecture Notes – Power points slides – Handout sheets • Text Book – STRUCTURAL ANALYSIS II, 7th Edition (2009) by R. C. Hibbeler TEXTBOOK’S INTERNET SITE: http://www.pearsonhighered.com/bookseller/product/Structural- Analysis/9780136020608.page
- 9. Reference • Any Structural Analysis Book • Structural Analysis, by Jack McCormac, Harper & Row Publisher, New York, 1984 • Fundamental of Structural Analysis, by H. West and L. Geschwindner, John Wihley & Sons, Inc., 1993.
- 10. Grading Policy • Homework and Quizzes 20% • Midterm Exam 30% • Final Exam 50% Exams Dates: Midterm Exam will be announced by the department Final Exam:
- 11. Introduction • What is statically DETERMINATE structure? – When all the forces (reactions) in a structure can be determined from the equilibrium equations its called statically determinate structure – Structure having unknown forces equal to the available equilibrium equations No. of unknown = 2 No. of equilibrium equations = 2 2 = 2 thus statically determinate
- 12. Introduction • What is statically INETERMINATED structure – Structure having more unknown forces than available equilibrium equations – Additional equations needed to solve the unknown reactions No. of unknown = 3 No. of equilibrium equations = 2 3 2 thus statically Indeterminate P
- 13. Indeterminate Structure Why we study indeterminate structure – Most of the structures designed today are statically indeterminate – Reinforced concrete buildings are considered in most cases as a statically indeterminate structures since the columns & beams are poured as continuous member through the joints & over the supports – More stable compare to determinate structure or in another word safer. – In many cases more economical than determinate. – The comparison in the next page will enlighten more
- 14. Contrast Indeterminate Structure Determinate Structure 14 Deflection P P 3 48 PL EI 3 192 PL EI 4 1 Stress P P 4 PL 8 PL 2 1 Considerable compared to indeterminate structure Generally smaller than determinate structure Less moment, smaller cross section & less material needed High moment caused thicker member & more material needed
- 15. Contrast Indeterminate Structure Determinate Structure Stability in case of over load P P Plastic Hinge Plastic Hinge Support will not develop the horizontal force & moments that necessary to prevent total collapse No load redistribution When the plastic hinge formed certain collapse for the system Will develop horizontal force & moment reactions that will hold the beam Has the tendency to redistribute its load to its redundant supports When the plastic hinge formed the system would be a determinate structure
- 16. Contrast Indeterminate Structure Determinate Structure Temperature P P Differential Displacement P P No effect & no stress would be developed in the beam No effect & no stress would be developed Serious effect and stress would be developed in the beam Serious effect and stress would be developed
- 17. Flexibility method of analysis