1. Mechanics of Materials
ميكانيكا المواد
Mechanics of Materials

2. Office Hours Mechanics of Materials 3, 0, 3 Required Core Course
Strength of Materials
Lec. 1
Course ID
Course Name
Hours
Course Type
803323
Mechanics of Materials
3, 0, 3
Required Core Course
Instructor
Office
Extension
Mohammed A Alsabban
G1153, Building G
1142
Office Hours
Monday
11:00am-12:00 noon
Grading توزيع الدرجات
HW 10% الواجبات
Attendance 10% الحضور
1st MT 15% يوم 27 شعبان
2nd MT 15% يوم 19 رمضان
Final 50% يوم 17 شوال

3. Class/Lab Schedule
Theory Section 1: Sun & Mon 1:00pm – 2:40 pm
Teaching Assistance Section 1: Wed 1:00pm–2:40pm
Course Objective
Student learns how to calculate the stresses, strains and displacements in material due to external axial, bending and torsional loads. The student gets the ability to use these techniques to obtain maximum stress at a point and in designing simple structural elements.
Course Description
(Catalogue)
Concept of stress and strain, state of stress and strain at a point, equilibrium, stress–strain and strain displacement relationship. Two-dimensional problems. Stress transformation. Shear force and bending moment relations and diagrams. Torsion, Combined loading, Statically indeterminate problems, Energy method and stability.

4. Statics (803-221) Course Contents (Catalogue) Prerequisite courses
Stresses and strains due to axial loads, stress-strain diagram, hook’s law, moment, shear, two and three dimension problems. The relation between the forces and bending moment and shear forces. Reactions in beams, shear in beams, bending moment and shear force reactions in beams. Moment of inertia, shear stress, Principle stresses, strain–displacement relationship, Mohr’s circle to determine stresses and strain. Torsional moment, shear due to torsion – statically indeterminate problems. Energy method and stability.
Prerequisite courses
Statics ( )
Textbook References
Hibbeler, R. C., “Mechanics of Materials”, Seventh SI edition, Pearson, 2009
Lectures are presented using power point and copies are sent to students' s

5. تقديم Introduction
Mechanics of Materials is the study of the internal effect of external forces applied to structural member. Stress, strain, deformation deflection, torsion, flexure, shear diagram, and moment diagram, topics covered by this subject.دراسة تأثير القوى الخارجية على المادة داخليا، الاجهاد والانفعال والتشوه وتغير الحجم، الالتواء والانثناء، القص والعزوم وابرازهم بيانيا
Materialsدراسة المواد المتوفرة
Stiffness (deformation characteristics)مقاومة المادة لتغير الحجم والشكل تحت تأثير القوى الخارجية
Stability (of load-carrying members)اتزان الأعضاء

6. دراسة خصائص الموادCharacteristics of Materials
Laboratory تتم في معامل
Specimens بأخذ عينات قياسية
Testواجراء اختبارات قياسية
Behaviorورصد
Physical Characteristics وتحديد الخصائص الميكانيكية

7. Method of Sections طريقة المقاطع
Internal resistance of a bodyمقاومة داخلية
Forces within to balance external forcesقوى داخلية توازن القوى الخارجية
Stable body at rest is in equilibriumالجسم الساكن جسم مستقر
Arbitrary section (suggested where?)مقطع اختياري
Body divided into partsيقطع الجسم الى أجزاء
Parts must also be in equilibrium الاجزاء المقطوعة في حالة اتزان
External forces are balanced by the internal forcesالقوى الداخلية تتوازن مع القوى الخارجية
Free Body Diagram (FBD)رسم حر للنظام يساعد في تحليله

9. Stressالإجهاد
Stress : Intensity of Force, or force divided by area [N/m2], called [Pascal]الاجهاد شدة القوة على وحدة مساحة
Perpendicular and Parallel resolution of stressعمودي أو موازي للسطح

10. اجهاد رأسي (عمودي) Normal Stress σ

11. Normal Stress σ
Tension force produces tensile stresses to lengthen the member.قوة الشد ينتج عنها اجهاد شد ويطيل من العضو
Compressive force produces compressive stresses to shorten the member.قوة الضغط ينتج عنها اجهاد ضغط ينقص من طول العضو

12. اجهاد القص Shear Stress τ
Parallel to plane موازي للسطح

13. The most general state of stress acting on an element

14. Equilibriumالاتزان
If the body as a whole is in equilibrium, any part of it must also be in equilibrium.الجسم المتزن أي جزء مقطوع منه متزن
∑ F external = ∑ F internal
مجموع القوى الخارجية تساوي
مجموع القوى الداخلية

15. Area [m2 or mm2] Stress [Pascal, Pa] Pa = Pascal = Units (SI)
Strength of Materials
Lec. 1
Units (SI)
Force [ Newton, N]
Area [m2 or mm2]
Stress [Pascal, Pa]
Pa = Pascal =
MPa = Mega Pascal =

17. The most general state of stress acting on an element

18. Axial Load and Normal Stress
Stress is maximum when plane of cut is perpendicular to force.
Axial loads produces uniaxial stress
Loads acting through the centeroid of the cross-sectional area produces uniformly distributed stress

19. Average Shearing Stress
Stresses in the plane parallel to the applied force
Assuming uniformly distributed stress
The average shearing stress is

20. Critical Section
Section that have the minimum cross-sectional area and the greatest axial force
Maximum Stress occurs at the critical section

21. Equilibrium Equations
For 2-D (x-y plane) it is reduced to:

22. Determinate VS Indeterminate
Depending on the number of the unknown reactions a problem may be identified as:
Determinate Or
Indeterminate
Ways to solve problems will differ accordingly

23. Factor of Safety
For design purposes ultimate strength can NOT be applied directly and a factor of safety is introduced.
Reasons:
Not sure about magnitude of applied force
Assumed Uniformity of material is no exactly true.
Corrosion
Plastic deformation under sustained loads
Cyclic Loading and Fatigue
Residual Stresses

24. Review
Support Reactions

25. Review
Equilibrium:

26. Internal Resultant Loadings
Review
Internal Resultant Loadings

27. Review
Coplanar Loadings

28. Examples

41. Homework Problems

44. Review
Average normal stress

54. Review
Average shear stress

55. Pure Shear

63. Homework Problems

66. Review
Allowable Stress

68. Design of Simple Connections
Review
Design of Simple Connections

77. Homework Problems