Frames and Machines

Republic of Iraq
The Ministry of Higher Education & Scientific Research
Babylon University
College of Engineering
Electrochemical Engineering Department
1st Stage
Lecturer name: Sarmed Abdalrasoul Salih
Academic Status: Asst. Lect.
Qualification: M.Sc

Static and strength of material
Introduction for static
Mechanics is the physical science which deals with the effects of forces on objects. No other subject plays a greater role in engineering analysis than mechanics. Although the principles of mechanics are few, they have wide application in engineering. The principles of mechanics are central to research and development in the fields of vibrations, stability and strength of structures and machines, robotics rocket and spacecraft design, automatic control, engine performance, fluid flow, electrical machines and apparatus, and molecular atomic, and subatomic behavior.
Mechanic’s is the oldest of the physical sciences which deals with the effects of forces on objects. The early history of this subject is synonymous with the very beginnings of engineering. The earliest recorded writings in mechanics are those of Archimedes on the principle of the lever and the principle of buoyancy. Substantial progress came later with the formulation of the laws of vector combination of forces by Stevinus, who also formulated most of the principles of statics. The first investigation of a dynamics problem is credited to Galileo for his experiments with falling stones. The accurate formulation of the laws of motion, as well as the law of gravitation, was made by Newton who also conceived the idea of the infinitesimal in mathematical analysis.
The subject of mechanics is logically divided into two parts
1. Statics: statics is part of mechanics which concerns the equilibrium of bodies under the action of forces.
2. Dynamics: dynamics is a part of mechanics which concerns the motion of bodies.

Introduction for strength of material
At the present time, a decided change is taking place in the attitude of designers towards the application of analytical methods in the solution of engineering problems. Design is no longer based principally upon empirical formulas. The importance of analytical methods combined with laboratory experiments in the solution of technical problems is becoming generally accepted.
Types of machines and structures are changing very rapidly, especially in the new fields of industry, and usually time does not permit the accumulation of the necessary empirical data. The size and cost of structures at constantly increasing, which consequently creates a severe demand for greater reliability in structures. The economical factor in design under the present conditions of competition is becoming of growing importance. The construction must be sufficiently strong and reliable saving in material. Under such conditions, the problem of a designer becomes extremely difficult. Reduction in weight involves and increases in working stresses which can be safely allowed only on a basis of careful analysis of stress distribution in the structure and experimental investigation of the mechanical properties of the materials employed.