INTRODUCTION_TO_STATICS of rigid bodies.pptx

Engineering mechanics. Statics of Rigid Bodies

1. INTRODUCTION TO STATICS Dr. Ahmet KIRLI

2. Course Description :  The course covers the following topics ; statics of particles : forces in plane , forces in space , equilibrium , moment of a force , moment of a couple , equivalent systems of forces on rigid bodies , equilibrium in two dimensions , equilibrium in three dimensions , distributed forces : centroids and center of gravity , analysis of structures : trusses , frames and machines , internal forces in beams and cables , friction , moments of inertia of areas , moments of inertia of masses , method of virtual work .  Course Objectives : 1) To provide definition of force and moment vectors and give necessary vector algebra 2) To explain the concept of equilibrium of particles and rigid bodies in plane and 3D space 3) To give information about support types and to give ability to calculate support reactions 4) To explain the equilibrium of structures and internal forces in trusses , and frames 5) To give information about distributed loads 6) To provide information on moment of inertia 7) To explain virtual work concept .   

3. Chapter 1 INTRODUCTION Mechanics - the physical science which describes or predicts the conditions of rest or motion of bodies under the action of forces. A.Rigid bodies 1. S tatics 2.Dynamics B.Deformable bodies C.Fluid Mechanics 1. C ompressible - gas 2. I ncompressible - liquids Mechanics is the foundation of most engineering sciences mechanics is an applied science. The purpose of mechanics is to explain and predict physical phenomena and thus to lay the foundations for engineering applications.

4. Mechanics Of Rigid Bodies, It is the analysis of the actions of forces , 1. S tatics : the study of systems that are in a state of constant motion , either at rest or moving at a constant velocity a nd 2. D ynamics : the study of systems in which acceleration is present .

5. What is Rigid Body? Rigid body - a body is considered rigid when the relative movement between its parts are negligible. Assumptions In Statics we will assume the bodies to be perfectly rigid, no deformation.   This is never true in the real world, everything deforms a little when a load is applied.   These deformations are small and will not significantly affect the conditions of equilibrium or motion, so we will neglect the deformations.

6. Statics : are they in rest or in constant velocity ? or what should be the force to be able to identify this system as static ? Strength od Materials : What should be the cross section area ? Or what should be the material properties ? Dynamics : steady state response ? Transient response Frcition dynamics ? Vibration ?

7. 1- space - the geometric region occupied by bodies whose positions are described by linear and angular measurements relative to a coordinate system. 2- time - the measure of the succession of events 3- mass - the measure oaf the inertia of a body , It is the resistance to a change of motion. 4- force - the action of one body on another Basic concepts: space, time, mass, force Coordinate Systems : Cartesian : x, y, z Cylindrical : r, θ ,z Spherical : r, θ , ϕ

8. Newton developed the fundamentals of mechanics. The concepts above, space, time, and mass are absolute, independent of each other in Newtonian Mechanics. In   physics ,  classical mechanics  (also known as  Newtonian mechanics ) is one of two major sub-fields of  mechanics . The other sub-field is  quantum mechanics . Classical mechanics is concerned with the set of  physical laws  describing the motion of  bodies  under the influence of a system of  forces . Newtonian mechanics, along with  Lagrangian mechanics  and  Hamiltonian mechanics , as the three main formalisms of classical mechanics . Classical mechanics describes the motion of  macroscopic   objects such as  spacecraft ,  planets ,  stars  and  galaxies . classical mechanics are sub-fields, including those that describe the behavior of  solids ,  liquids  and  gases . Classical mechanics provides extremely accurate results when studying large objects and speeds not approaching the  speed of light . When the objects being examined are sufficiently small, it becomes necessary to introduce the other major sub-field of mechanics: quantum mechanics. 

9. Hamiltonian Mechanics - impulse and momentum Langrangian Mechanics - energy Newtonian Mechanics - forces Newton's laws of motion

10. System of Units Pounds in EU

11. What is the mass of an object that weighs 19.62 Newtons ? This is the difference between Mass and Weight. Example :

12. EXAMPLE