mechanics
The mechanics (by ancient Greek μηχανικὴ τέχνη mechané , German , machine trick mode of action ' ) is in the sciences and engineering sciences , the study of the movement of bodies , as well as the thereby acting forces . In physics , mechanics is usually understood to mean classical mechanics . In the subarea of theoretical physics , the term is often used in abbreviation for theoretical mechanics . In engineering, it is usually understood to mean technical mechanics , which uses the methods and fundamentals of classical mechanics to calculate machines or structures.
Both the theory of relativity and quantum mechanics contain classical mechanics as a special case.
The Classical Mechanics was in the 17th century mainly by the work of Isaac Newton founded and became the first science in the modern sense (see History of classical mechanics ).
Subdivision
Structuring the mechanics from the point of view of the forces involved 



Mechanics can be roughly subdivided into different subareas: Kinematics deals with the movement of bodies and primarily describes the trajectory , speed and acceleration of bodies without taking mass or forces into account. The dynamic extends the description of the movements through the mass and the acting forces . Dynamics are often divided into statics (forces in equilibrium) and kinetics (forces not in equilibrium). In technical mechanics, on the other hand, they are also divided into kinematics and kinetics and understood as a subarea that stands alongside statics.
In addition, special subareas of mechanics can be divided according to many different criteria.
The division already described above according to the consideration of forces results in:
 Kinematics  without considering forces
 Dynamics  taking forces into account
A classification according to the state of aggregation is as follows:
 Mechanics of solid bodies ( solid mechanics )
 Mechanics of rigid bodies or stereo mechanics : systems of discrete mass points and nondeformable bodies. It is divided into point mechanics , which refrains from self rotation of the body, and the gyro theory , which concentrates on the selfrotation.
 Mechanics of elastic bodies: The theory of elasticity deals with elastic deformations, i.e. deformations that recede after the forces causing them have been withdrawn like a spring. An important subarea is elastostatics for immobile bodies.
 Mechanics of plastic bodies: The theory of plasticity deals with plastic deformations, i.e. deformations that do not recede after the forces causing them have been removed, as with warm butter or forging.

Fluid mechanics ( gases and liquids ): It can be further subdivided according to the internal friction into the mechanics of ideal gases or real gases and the mechanics of frictionfree and viscous liquids, as well as according to the fluid and according to the movement in static (stationary, stationary) and dynamics (moving) :
 Fluid statics : aerostatics (for gases), hydrostatics (for liquids)
 Fluid dynamics : aerodynamics , hydrodynamics
The classification according to area of application leads to:

Theoretical mechanics (also called "analytical mechanics"). In addition to the division into kinematics and dynamics, the formalism can also be divided into:
 Newtonian mechanics : The oldest representation that goes back to Isaac Newton . It applies in unaccelerated reference systems ( inertial systems ). Solving specific problems with restricted mobility can be very timeconsuming.
 Lagrange formalism : A representation that goes back to JosephLouis Lagrange and is also valid in accelerated frames of reference. It uses generalized coordinates and allows a much simpler solution to many problems, e.g. B. in systems with more than two bodies or with restricted mobility.
 Hamiltonian mechanics : A very general presentation by William Rowan Hamilton , which has advantages in celestial mechanics and is suitable for the connection of quantum mechanics in the theoretical building of physics .

Technical mechanics . Usually divided into:
 Statics : Resting rigid bodies
 Strength theory : deformable solid bodies
 Dynamics : moving bodies
A classification according to the type of idealization includes:
 Point mechanics : It was founded by I. Newton and uses the highest possible idealization of real bodies as a mass point .
 Mechanics of rigid bodies or stereomechanics: nondeformable bodies and systems of mass points with six degrees of freedom with the subarea of gyro theory , which focuses on rotary movements with three degrees of freedom.

Continuum mechanics : continuously expanded, deformable bodies, with the subdivision:
 Mechanics of elastic bodies: The theory of elasticity deals with elastic deformations, i.e. deformations that recede after the forces causing them have been withdrawn like a spring. An important subarea is elastostatics for immobile bodies.
 Mechanics of plastic bodies: The theory of plasticity deals with plastic deformations, i.e. deformations that do not recede after the causative forces have been removed, as with warm butter or forging.
 Fluid mechanics and gas dynamics (fluid mechanics): liquids , gases and plasmas
 Statistical mechanics (also statistical thermodynamics): statistical interaction of many mass points, with particular reference to thermodynamics . Statistical mechanics is a branch of statistical physics .
Education
Mechanics is taught on the one hand as part of the physics course and on the other hand as part of engineering training, for example in the course of mechanical engineering or civil engineering . There are also a few special courses in mechanics, some of which are called Applied Mechanics :
 Master of Science (MSc) Mechanics from Ecole Polytechnique , France
 MSc Mechanics at the Universite ParisSaclay , France
 MSc Applied Mechanics at TU Chalmers , Sweden
 Mechanics study area with Bachelor of Science (BSc) Applied Mechanics and MSc Mechanics at TU Darmstadt
 MSc Computational Mechanics at the University of DuisburgEssen
 MSc Computational Mechanics at the Technical University of Munich
 BSc and MSc mechanical engineering with specialization in applied mechanics at the Ruhr University Bochum
Connections to related scientific disciplines
Connections to other scientific disciplines arise between classical mechanics and some scientific disciplines, as well as between technical mechanics and engineering disciplines.
Connections in the natural sciences
In biology is the biomechanics a special application of mechanics and the chemistry the reaction kinetics , which deals with kinetic energies of reactants and chemical reactions.
In the theoretical structure of physics, there are diverse connections: Hamilton mechanics is a very general formulation of classical mechanics which contains both Newtonian mechanics and quantum mechanics as special cases . Systems that consist of a large number of bodies can theoretically be described by the movements of the individual bodies. In practice, the solution of the numerous equations that are required is no longer possible from a certain number of bodies; the Statistical Mechanics then deals with statements such manybody systems . From a size of about 10 ^{23} particles, the predictions of statistical mechanics agree very well with those of thermodynamics . The theory of relativity contains classical mechanics as a special case for small speeds.
Connections in engineering
Technical mechanics basically provides general calculation methods without going into special construction materials (only parameters such as strength and elasticity are taken into account, but not whether it is wood or steel) and does not deal with special components.
Findings from the independent engineering discipline of materials technology are integrated into strength theory , which is a field of technical mechanics.
In mechanical engineering, the field of machine elements (screws, gears, etc.) is very close to mechanics. There are special equations for calculating the necessary dimensions for the respective machine elements. The driving dynamics is both part of the dynamics and the vehicle technology . The Mechatronics is an interdisciplinary field that consists of shares of mechanics / mechanical and electrical engineering. Special areas of technical mechanics in mechanical engineering are machine dynamics and rotor dynamics . In gas turbines , fluid mechanics (aerodynamics) is so closely related to thermodynamics that it is sometimes referred to as aerothermodynamics.
In civil engineering has a special affinity for the structural analysis of the structural civil engineering on. This takes into account the peculiarities of special building materials and is divided into timber and steel construction as well as concrete and reinforced concrete construction , while structural engineering creates and provides calculation methods that are independent of the construction method and are therefore a fundamental technical and scientific discipline. Further areas are soil mechanics , rock mechanics and subsoil dynamics .
Web links
Individual evidence
 ^ Heinz Dieter Motz: Engineering Mechanics: Technical Mechanics for Study and Practice . SpringerVerlag, March 8, 2013, ISBN 9783642957611 , p. 1.
 ↑ Jürgen Mittelstraß: The Greek way of thinking: From the emergence of philosophy from the spirit of geometry . De Gruyter, 2014, ISBN 9783110370621 , p. 29.
 ↑ Sayir, businessman: engineering mechanics. Springer, 2015, 2nd edition, p. 9.
 ^ R. Mahnken: Textbook of technical mechanics. Volume 1: Statics. Springer, 2012, p. 5.
 ↑ ^{a } ^{b} Georg Hamel : Elementary Mechanics . A textbook. BG Teubner, Leipzig and Berlin 1912, p. 74 ( archive.org [accessed February 26, 2020]).
 ↑ Wolfgang Nolting: Basic Course Theoretical Physics 2. Analytical Mechanics. 9th edition, p. IX, 105 f.
 ↑ Honerkamp, Römer: Classical Theoretical Physics. 4th edition, foreword and p. 69.
 ↑ Hans Rick: Gas turbines and aircraft propulsion. Springer, 2013, p. 35.
 ↑ Dinkler: Basics of structural engineering. 4th edition. Springer, 2016, p. 3.
 ^ Peter Marti : structural analysis. Ernst & Sohn , 2012, p. 4.
 ^ Peter Marti: structural analysis. Ernst & Sohn, 2012, p. 1.
 ^ KarlEugen Kurrer : History of structural engineering. In search of balance . Ernst & Sohn, 2016, p. 15