Stress-strain graph: It's a graph which represents stress value against strain value of the given material,when the material is subjected to increasing pull. There are mainly six points in the graph.
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Deformation in continuum mechanics is the transformation of a body from a reference configuration to a current configuration.[1] A configuration is a set containing the positions of all particles of the body.
A deformation may be caused by external loads,[2]body forces (such as gravity or electromagnetic forces), or changes in temperature, moisture content, or chemical reactions, etc.
Strain is a description of deformation in terms of relative displacement of particles in the body that excludes rigid-body motions. Different equivalent choices may be made for the expression of a strain field depending on whether it is defined with respect to the initial or the final configuration of the body and on whether the metric tensor or its dual is considered.
In a continuous body, a deformation field results from a stress field induced by applied forces or is due to changes in the temperature field inside the body. The relation between stresses and induced strains is expressed by constitutive equations, e.g., Hooke's law for linear elastic materials. Deformations which are recovered after the stress field has been removed are called elastic deformations. In this case, the continuum completely recovers its original configuration. On the other hand, irreversible deformations remain even after stresses have been removed. One type of irreversible deformation is plastic deformation, which occurs in material bodies after stresses have attained a certain threshold value known as the elastic limit or yield stress, and are the result of slip, or dislocation mechanisms at the atomic level. Another type of irreversible deformation is viscous deformation, which is the irreversible part of viscoelastic deformation.
In the case of elastic deformations, the response function linking strain to the deforming stress is the compliance tensor of the material.
- 1Strain
- 1.1Strain measures
- 1.2Normal and shear strain
- 2Description of deformation
- 3Displacement
- 4Examples of deformations
- 4.1Plane deformation
Strain[edit]
Strain is a measure of deformation representing the displacement between particles in the body relative to a reference length.
A general deformation of a body can be expressed in the form x = F(X) where X is the reference position of material points in the body. Such a measure does not distinguish between rigid body motions (translations and rotations) and changes in shape (and size) of the body. A deformation has units of length.
We could, for example, define strain to be
where I is the identity tensor.Hence strains are dimensionless and are usually expressed as a decimal fraction, a percentage or in parts-per notation. Strains measure how much a given deformation differs locally from a rigid-body deformation.[3]
A strain is in general a tensor quantity. Physical insight into strains can be gained by observing that a given strain can be decomposed into normal and shear components. The amount of stretch or compression along material line elements or fibers is the normal strain, and the amount of distortion associated with the sliding of plane layers over each other is the shear strain, within a deforming body.[4] This could be applied by elongation, shortening, or volume changes, or angular distortion.[5]
The state of strain at a material point of a continuum body is defined as the totality of all the changes in length of material lines or fibers, the normal strain, which pass through that point and also the totality of all the changes in the angle between pairs of lines initially perpendicular to each other, the shear strain, radiating from this point. However, it is sufficient to know the normal and shear components of strain on a set of three mutually perpendicular directions.
If there is an increase in length of the material line, the normal strain is called tensile strain, otherwise, if there is reduction or compression in the length of the material line, it is called compressive strain.
Strain measures[edit]
Depending on the amount of strain, or local deformation, the analysis of deformation is subdivided into three deformation theories:
- Finite strain theory, also called large strain theory, large deformation theory, deals with deformations in which both rotations and strains are arbitrarily large. In this case, the undeformed and deformed configurations of the continuum are significantly different and a clear distinction has to be made between them. This is commonly the case with elastomers, plastically-deforming materials and other fluids and biological soft tissue.
- Infinitesimal strain theory, also called small strain theory, small deformation theory, small displacement theory, or small displacement-gradient theory where strains and rotations are both small. In this case, the undeformed and deformed configurations of the body can be assumed identical. The infinitesimal strain theory is used in the analysis of deformations of materials exhibiting elastic behavior, such as materials found in mechanical and civil engineering applications, e.g. concrete and steel.
- Large-displacement or large-rotation theory, which assumes small strains but large rotations and displacements.
In each of these theories the strain is then defined differently. The engineering strain is the most common definition applied to materials used in mechanical and structural engineering, which are subjected to very small deformations. On the other hand, for some materials, e.g. elastomers and polymers, subjected to large deformations, the engineering definition of strain is not applicable, e.g. typical engineering strains greater than 1%,[6] thus other more complex definitions of strain are required, such as stretch, logarithmic strain, Green strain, and Almansi strain.
Engineering strain[edit]
The Cauchy strain or engineering strain is expressed as the ratio of total deformation to the initial dimension of the material body in which the forces are being applied. The engineering normal strain or engineering extensional strain or nominal straine of a material line element or fiber axially loaded is expressed as the change in length ΔL per unit of the original length L of the line element or fibers. The normal strain is positive if the material fibers are stretched and negative if they are compressed. Thus, we have
where e is the engineering normal strain, L is the original length of the fiber and l is the final length of the fiber. Measures of strain are often expressed in parts per million or microstrains.
The true shear strain is defined as the change in the angle (in radians) between two material line elements initially perpendicular to each other in the undeformed or initial configuration. The engineering shear strain is defined as the tangent of that angle, and is equal to the length of deformation at its maximum divided by the perpendicular length in the plane of force application which sometimes makes it easier to calculate.
Stretch ratio[edit]
The stretch ratio or extension ratio is a measure of the extensional or normal strain of a differential line element, which can be defined at either the undeformed configuration or the deformed configuration. It is defined as the ratio between the final length l and the initial length L of the material line.
The extension ratio is approximately related to the engineering strain by
This equation implies that the normal strain is zero, so that there is no deformation when the stretch is equal to unity.
The stretch ratio is used in the analysis of materials that exhibit large deformations, such as elastomers, which can sustain stretch ratios of 3 or 4 before they fail. On the other hand, traditional engineering materials, such as concrete or steel, fail at much lower stretch ratios.
True strain[edit]
The logarithmic strainε, also called, true strain or Hencky strain[7]. Considering an incremental strain (Ludwik)
the logarithmic strain is obtained by integrating this incremental strain:
where e is the engineering strain. The logarithmic strain provides the correct measure of the final strain when deformation takes place in a series of increments, taking into account the influence of the strain path.[4]
Green strain[edit]
The Green strain is defined as:
Almansi strain[edit]
The Euler-Almansi strain is defined as
Normal and shear strain[edit]
Strains are classified as either normal or shear. A normal strain is perpendicular to the face of an element, and a shear strain is parallel to it. These definitions are consistent with those of normal stress and shear stress.
Normal strain[edit]
For an isotropic material that obeys Hooke's law, a normal stress will cause a normal strain. Normal strains produce dilations.
Consider a two-dimensional, infinitesimal, rectangular material element with dimensions dx × dy, which, after deformation, takes the form of a rhombus. The deformation is described by the displacement fieldu. From the geometry of the adjacent figure we have
and
For very small displacement gradients the squares of the derivatives are negligible and we have
The normal strain in the x-direction of the rectangular element is defined by
Similarly, the normal strain in the y- and z-directions becomes
Shear strain[edit]
Shear strain | |
---|---|
Common symbols | γ or ε |
SI unit | 1, or radian |
γ = τ/G |
The engineering shear strain (γxy) is defined as the change in angle between lines AC and AB. Therefore,
From the geometry of the figure, we have
For small displacement gradients we have
For small rotations, i.e. α and β are ≪ 1 we have tan α ≈ α, tan β ≈ β. Therefore,
thus
By interchanging x and y and ux and uy, it can be shown that γxy = γyx.
Similarly, for the yz- and xz-planes, we have
The tensorial shear strain components of the infinitesimal strain tensor can then be expressed using the engineering strain definition, γ, as
Metric tensor[edit]
A strain field associated with a displacement is defined, at any point, by the change in length of the tangent vectors representing the speeds of arbitrarily parametrized curves passing through that point. A basic geometric result, due to Fréchet, von Neumann and Jordan, states that, if the lengths of the tangent vectors fulfil the axioms of a norm and the parallelogram law, then the length of a vector is the square root of the value of the quadratic form associated, by the polarization formula, with a positive definitebilinear map called the metric tensor.
Description of deformation[edit]
Deformation is the change in the metric properties of a continuous body, meaning that a curve drawn in the initial body placement changes its length when displaced to a curve in the final placement. If none of the curves changes length, it is said that a rigid body displacement occurred.
It is convenient to identify a reference configuration or initial geometric state of the continuum body which all subsequent configurations are referenced from. The reference configuration need not be one the body actually will ever occupy. Often, the configuration at t = 0 is considered the reference configuration, κ0(B). The configuration at the current time t is the current configuration.
For deformation analysis, the reference configuration is identified as undeformed configuration, and the current configuration as deformed configuration. Additionally, time is not considered when analyzing deformation, thus the sequence of configurations between the undeformed and deformed configurations are of no interest.
The components Xi of the position vector X of a particle in the reference configuration, taken with respect to the reference coordinate system, are called the material or reference coordinates. On the other hand, the components xi of the position vector x of a particle in the deformed configuration, taken with respect to the spatial coordinate system of reference, are called the spatial coordinates
There are two methods for analysing the deformation of a continuum. One description is made in terms of the material or referential coordinates, called material description or Lagrangian description. A second description is of deformation is made in terms of the spatial coordinates it is called the spatial description or Eulerian description.
There is continuity during deformation of a continuum body in the sense that:
- The material points forming a closed curve at any instant will always form a closed curve at any subsequent time.
- The material points forming a closed surface at any instant will always form a closed surface at any subsequent time and the matter within the closed surface will always remain within.
Affine deformation[edit]
A deformation is called an affine deformation if it can be described by an affine transformation. Such a transformation is composed of a linear transformation (such as rotation, shear, extension and compression) and a rigid body translation. Affine deformations are also called homogeneous deformations.[8]
Therefore, an affine deformation has the form
where x is the position of a point in the deformed configuration, X is the position in a reference configuration, t is a time-like parameter, F is the linear transformer and c is the translation. In matrix form, where the components are with respect to an orthonormal basis,
The above deformation becomes non-affine or inhomogeneous if F = F(X,t) or c = c(X,t).
Rigid body motion[edit]
A rigid body motion is a special affine deformation that does not involve any shear, extension or compression. The transformation matrix F is proper orthogonal in order to allow rotations but no reflections.
A rigid body motion can be described by
where
In matrix form,
Displacement[edit]
A change in the configuration of a continuum body results in a displacement. The displacement of a body has two components: a rigid-body displacement and a deformation. A rigid-body displacement consists of a simultaneous translation and rotation of the body without changing its shape or size. Deformation implies the change in shape and/or size of the body from an initial or undeformed configuration κ0(B) to a current or deformed configuration κt(B) (Figure 1).
If after a displacement of the continuum there is a relative displacement between particles, a deformation has occurred. On the other hand, if after displacement of the continuum the relative displacement between particles in the current configuration is zero, then there is no deformation and a rigid-body displacement is said to have occurred.
The vector joining the positions of a particle P in the undeformed configuration and deformed configuration is called the displacement vectoru(X,t) = uiei in the Lagrangian description, or U(x,t) = UJEJ in the Eulerian description.
A displacement field is a vector field of all displacement vectors for all particles in the body, which relates the deformed configuration with the undeformed configuration. It is convenient to do the analysis of deformation or motion of a continuum body in terms of the displacement field. In general, the displacement field is expressed in terms of the material coordinates as
or in terms of the spatial coordinates as
where αJi are the direction cosines between the material and spatial coordinate systems with unit vectors EJ and ei, respectively. Thus
and the relationship between ui and UJ is then given by
Knowing that
then
It is common to superimpose the coordinate systems for the undeformed and deformed configurations, which results in b = 0, and the direction cosines become Kronecker deltas:
Thus, we have
or in terms of the spatial coordinates as
Displacement gradient tensor[edit]
The partial differentiation of the displacement vector with respect to the material coordinates yields the material displacement gradient tensor∇XU. Thus we have:
or |
where F is the deformation gradient tensor.
Similarly, the partial differentiation of the displacement vector with respect to the spatial coordinates yields the spatial displacement gradient tensor∇xU. Thus we have,
or |
Examples of deformations[edit]
Homogeneous (or affine) deformations are useful in elucidating the behavior of materials. Some homogeneous deformations of interest are
Plane deformations are also of interest, particularly in the experimental context.
Plane deformation[edit]
A plane deformation, also called plane strain, is one where the deformation is restricted to one of the planes in the reference configuration. If the deformation is restricted to the plane described by the basis vectors e1, e2, the deformation gradient has the form
In matrix form,
From the polar decomposition theorem, the deformation gradient, up to a change of coordinates, can be decomposed into a stretch and a rotation. Since all the deformation is in a plane, we can write[8]
where θ is the angle of rotation and λ1, λ2 are the principal stretches.
Isochoric plane deformation[edit]
If the deformation is isochoric (volume preserving) then det(F) = 1 and we have
Alternatively,
Simple shear[edit]
A simple shear deformation is defined as an isochoric plane deformation in which there is a set of line elements with a given reference orientation that do not change length and orientation during the deformation.[8]
If e1 is the fixed reference orientation in which line elements do not deform during the deformation then λ1 = 1 and F·e1 = e1.Therefore,
Since the deformation is isochoric,
Define
Then, the deformation gradient in simple shear can be expressed as
Now,
Since
we can also write the deformation gradient as
See also[edit]
References[edit]
- ^Truesdell, C.; Noll, W. (2004). The non-linear field theories of mechanics (3rd ed.). Springer. p. 48.
- ^Wu, H.-C. (2005). Continuum Mechanics and Plasticity. CRC Press. ISBN1-58488-363-4.
- ^Lubliner, Jacob (2008). Plasticity Theory(PDF) (Revised ed.). Dover Publications. ISBN0-486-46290-0. Archived from the original(PDF) on 2010-03-31.
- ^ abRees, David (2006). Basic Engineering Plasticity: An Introduction with Engineering and Manufacturing Applications. Butterworth-Heinemann. ISBN0-7506-8025-3. Archived from the original on 2017-12-22.
- ^'Earth.'Encyclopædia Britannica from Encyclopædia Britannica 2006 Ultimate Reference Suite DVD .[2009].
- ^Rees, David (2006). Basic Engineering Plasticity: An Introduction with Engineering and Manufacturing Applications. Butterworth-Heinemann. p. 41. ISBN0-7506-8025-3. Archived from the original on 2017-12-22.
- ^Hencky, H. (1928). 'Über die Form des Elastizitätsgesetzes bei ideal elastischen Stoffen'. Zeitschrift für technische Physik. 9: 215–220.
- ^ abcOgden, R. W. (1984). Non-linear Elastic Deformations. Dover.
Further reading[edit]
- Bazant, Zdenek P.; Cedolin, Luigi (2010). Three-Dimensional Continuum Instabilities and Effects of Finite Strain Tensor, chapter 11 in 'Stability of Structures', 3rd ed. Singapore, New Jersey, London: World Scientific Publishing. ISBN9814317039.
- Dill, Ellis Harold (2006). Continuum Mechanics: Elasticity, Plasticity, Viscoelasticity. Germany: CRC Press. ISBN0-8493-9779-0.
- Hutter, Kolumban; Jöhnk, Klaus (2004). Continuum Methods of Physical Modeling. Germany: Springer. ISBN3-540-20619-1.
- Jirasek, M; Bazant, Z.P. (2002). Inelastic Analysis of Structures. London and New York: J. Wiley & Sons. ISBN0471987166.
- Lubarda, Vlado A. (2001). Elastoplasticity Theory. CRC Press. ISBN0-8493-1138-1.
- Macosko, C. W. (1994). Rheology: principles, measurement and applications. VCH Publishers. ISBN1-56081-579-5.
- Mase, George E. (1970). Continuum Mechanics. McGraw-Hill Professional. ISBN0-07-040663-4.
- Mase, G. Thomas; Mase, George E. (1999). Continuum Mechanics for Engineers (2nd ed.). CRC Press. ISBN0-8493-1855-6.
- Nemat-Nasser, Sia (2006). Plasticity: A Treatise on Finite Deformation of Heterogeneous Inelastic Materials. Cambridge: Cambridge University Press. ISBN0-521-83979-3.
- Prager, William (1961). Introduction to Mechanics of Continua. Boston: Ginn and Co. ISBN0486438090.
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strain 1
(strān)v.tr.1.strain 2
(strān)n.1. Biologystrain
(streɪn) vbstrain
(streɪn) nstrain1
(streɪn)v.t.
strain2
(streɪn)n.
strain3
(streɪn)n.
strain
(strān)Strain
a family of people or animals; a group of plants bred away from the original species.strain
Past participle: strained
Gerund: straining
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strain
Noun | 1. | strain - (physics) deformation of a physical body under the action of applied forces natural philosophy, physics - the science of matter and energy and their interactions; 'his favorite subject was physics' deformation - alteration in the shape or dimensions of an object as a result of the application of stress to it |
2. | strain - difficulty that causes worry or emotional tension; 'she endured the stresses and strains of life'; 'he presided over the economy during the period of the greatest stress and danger'- R.J.Samuelson difficulty - a condition or state of affairs almost beyond one's ability to deal with and requiring great effort to bear or overcome; 'grappling with financial difficulties' | |
3. | strain - a succession of notes forming a distinctive sequence; 'she was humming an air from Beethoven' melodic line, melodic phrase, melody, tune, air, line tucket, fanfare, flourish - (music) a short lively tune played on brass instruments; 'he entered to a flourish of trumpets'; 'her arrival was greeted with a rousing fanfare' glissando - a rapid series of ascending or descending notes on the musical scale roulade - (music) an elaborate run of several notes sung to one syllable music - an artistic form of auditory communication incorporating instrumental or vocal tones in a structured and continuous manner leitmotif, leitmotiv - a melodic phrase that accompanies the reappearance of a person or situation (as in Wagner's operas) theme song - a melody that recurs and comes to represent a musical play or movie signature tune, theme song, signature - a melody used to identify a performer or a dance band or radio/tv program melodic theme, musical theme, theme, idea - (music) melodic subject of a musical composition; 'the theme is announced in the first measures'; 'the accompanist picked up the idea and elaborated it' part, voice - the melody carried by a particular voice or instrument in polyphonic music; 'he tried to sing the tenor part' | |
4. | strain - (psychology) nervousness resulting from mental stress; 'his responsibilities were a constant strain'; 'the mental strain of staying alert hour after hour was too much for him' mental strain, nervous strain psychological science, psychology - the science of mental life nerves, nervousness - an uneasy psychological state; 'he suffered an attack of nerves' tension, stress, tenseness - (psychology) a state of mental or emotional strain or suspense; 'he suffered from fatigue and emotional tension'; 'stress is a vasoconstrictor' | |
5. | strain - a special variety of domesticated animals within a species; 'he experimented on a particular breed of white rats'; 'he created a new strain of sheep' animal group - a group of animals variety - (biology) a taxonomic category consisting of members of a species that differ from others of the same species in minor but heritable characteristics; 'varieties are frequently recognized in botany' pedigree - line of descent of a purebred animal species - (biology) taxonomic group whose members can interbreed | |
6. | strain - (biology) a group of organisms within a species that differ in trivial ways from similar groups; 'a new strain of microorganisms' biological science, biology - the science that studies living organisms taxon, taxonomic category, taxonomic group - animal or plant group having natural relations species - (biology) taxonomic group whose members can interbreed | |
7. | strain - injury to a muscle (often caused by overuse); results in swelling and pain harm, hurt, injury, trauma - any physical damage to the body caused by violence or accident or fracture etc. | |
8. | strain - the general meaning or substance of an utterance; 'although I disagreed with him I could follow the tenor of his argument' meaning, substance - the idea that is intended; 'What is the meaning of this proverb?' purport, drift - the pervading meaning or tenor; 'caught the general drift of the conversation' | |
9. | strain - an effortful attempt to attain a goal attempt, effort, try, endeavor, endeavour - earnest and conscientious activity intended to do or accomplish something; 'made an effort to cover all the reading material'; 'wished him luck in his endeavor'; 'she gave it a good try' jehad, jihad - a holy struggle or striving by a Muslim for a moral or spiritual or political goal | |
10. | strain - an intense or violent exertion elbow grease, exertion, effort, travail, sweat - use of physical or mental energy; hard work; 'he got an A for effort'; 'they managed only with great exertion' | |
11. | strain - the act of singing; 'with a shout and a song they marched up to the gates' vocal music - music that is vocalized (as contrasted with instrumental music) carol - a joyful song (usually celebrating the birth of Christ) cradlesong, lullaby - the act of singing a quiet song to lull a child to sleep | |
Verb | 1. | strain - to exert much effort or energy; 'straining our ears to hear' extend oneself - strain to the utmost kill oneself, overexert oneself - strain oneself more than is healthy labor, labour, tug, push, drive - strive and make an effort to reach a goal; 'She tugged for years to make a decent living'; 'We have to push a little to make the deadline!'; 'She is driving away at her doctoral thesis' bother, inconvenience oneself, trouble oneself, trouble - take the trouble to do something; concern oneself; 'He did not trouble to call his mother on her birthday'; 'Don't bother, please' |
2. | strain - test the limits of; 'You are trying my patience!' afflict - cause great unhappiness for; distress; 'she was afflicted by the death of her parents' | |
3. | strain - use to the utmost; exert vigorously or to full capacity; 'He really extended himself when he climbed Kilimanjaro'; 'Don't strain your mind too much' apply, employ, use, utilise, utilize - put into service; make work or employ for a particular purpose or for its inherent or natural purpose; 'use your head!'; 'we only use Spanish at home'; 'I can't use this tool'; 'Apply a magnetic field here'; 'This thinking was applied to many projects'; 'How do you utilize this tool?'; 'I apply this rule to get good results'; 'use the plastic bags to store the food'; 'He doesn't know how to use a computer' overextend, overstrain - strain excessively; 'He overextended himself when he accepted the additional assignment' task, tax - use to the limit; 'you are taxing my patience' | |
4. | strain - separate by passing through a sieve or other straining device to separate out coarser elements; 'sift the flour' separate - divide into components or constituents; 'Separate the wheat from the chaff' rice - sieve so that it becomes the consistency of rice; 'rice the potatoes' riddle, screen - separate with a riddle, as grain from chaff winnow, fan - separate the chaff from by using air currents; 'She stood there winnowing chaff all day in the field' | |
5. | strain - cause to be tense and uneasy or nervous or anxious; 'he got a phone call from his lawyer that tensed him up' affect - act physically on; have an effect upon; 'the medicine affects my heart rate' stretch, extend - extend one's limbs or muscles, or the entire body; 'Stretch your legs!'; 'Extend your right arm above your head' make relaxed, unlax, unstrain, unwind, relax, loosen up - cause to feel relaxed; 'A hot bath always relaxes me' | |
6. | strain - become stretched or tense or taut; 'the bodybuilder's neck muscles tensed;' 'the rope strained when the weight was attached' tighten - become tight or tighter; 'The rope tightened' | |
7. | strain - remove by passing through a filter; 'filter out the impurities' separate - divide into components or constituents; 'Separate the wheat from the chaff' | |
8. | strain - rub through a strainer or process in an electric blender; 'puree the vegetables for the baby' cookery, cooking, preparation - the act of preparing something (as food) by the application of heat; 'cooking can be a great art'; 'people are needed who have experience in cookery'; 'he left the preparation of meals to his wife' rub - move over something with pressure; 'rub my hands'; 'rub oil into her skin' | |
9. | strain - alter the shape of (something) by stress; 'His body was deformed by leprosy' shape, form - give shape or form to; 'shape the dough'; 'form the young child's character' jaundice - distort adversely; 'Jealousy had jaundiced his judgment' |
strain
1nounworryease, relaxation, effortlessness, lack of tension
striverest, relax, idle, take it easy, slacken
strain
2nounstrain 1
verbTo exert one's mental or physical powers, usually under difficulty and to the point of exhaustion:strain 2
nounstrain
1[streɪn]A.Nthe strain on a rope → la tensión de una cuerda
this puts a strain on the cable → esto tensa el cable
that puts a great strain on the beam → esto pone mucha presión sobre la viga
to take the strain (lit) → aguantar el peso
to take the strain off [+ rope, cable] → disminuir la tensión de; [+ beam, bridge, structure] → disminuir la presión sobre
to break under the strain [rope, cable] → romperse debido a latensión
to collapse under the strain [bridge, ceiling] → venirse abajo debido a lapresión
I found it a strain being totally responsible for the child → me suponía una cargallevar toda la responsabilidaddelniño yo solo
it was a strain on the economy/his purse → suponía una carga para la economía/su bolsillo
the strains on the economy → las presiones sobre la economía
the strains of modern life → las tensionesde lavidamoderna
mental strain → cansanciommental
to put a strain on [+ resources] → suponer una carga para; [+ system] → forzar al límite; [+ relationship] → creartirantezortensiones en
it put a great strain on their friendship → creó mucha tirantez en su amistad
his illness has put a terrible strain on the family → su enfermedad ha creado mucha tensiónorestrés para la familia
he has been under a great deal of strain → ha estadosometido a mucha presión
see alsostress
the strain of climbing the stairs → el esfuerzo de subir las escaleras
back strain → torcedura de espalda
muscle strain →
he knew tennis put a strain on his heart → sabía que el tenis le sometía el corazón a un esfuerzoor le forzaba el corazón
see alsoeyestrain, repetitive
we could hear the gentle strains of a Haydn quartet → oíamos los suavescompases de un cuarteto de Haydn
the bride came in to the strains of the wedding march → la noviaentró al son or a los compasesde lamarchanupcial
the demands of the welfare state are straining public finances to the limit → las exigenciasdelestado de bienestar están resultando una cargaexcesiva para las arcaspúblicas
to strain relations with sb → tensar las relaciones con algn
to strain a muscle → hacerse un esguince
to strain o.s.: you shouldn't strain yourself → no deberíashacer mucha fuerza
he strained himself lifting something → se hizodañolevantando algo
don't strain yourself! (iro) → ¡no te vayas a quebraror herniar!
to strain one's ears to hear sth → aguzar el oído para oír algo
to strain every nerveorsinew to do sth → esforzarse mucho por hacer algo, hacergrandesesfuerzos por hacer algo
to strain sth into a bowl → colar algo en un cuenco
strain the mixture through a sieve → pase la mezcla por un tamiz
he strained to hear what she was saying → se esforzaba por oírlo quedecía
he strained against the bonds that held him (liter) → hacíaesfuerzos para soltarsede lascadenas que lo retenían
to strain at sth → tirar de algo
to strain at the leash [dog] → (fig) → saltar de impaciencia
to strain under a weight → ir agobiado por un peso
strain
2[streɪn]Nevery year new strains of flu develop → cada añoaparecennuevostipos de gripe
there is a strain of madness in the family → tienenvena de locosen lafamilia
there is a strain of cynicism in her writing → hay cierta vena de cinismo en sus escritos
strain
[ˈstreɪn]nto put a strain on sb → mettre les nerfs de qn à rudeépreuve
to put a strain on sth [+ relationship, organization, system] → mettre qch à rudeépreuve, peser sur qch
This policy puts a greater strain on the economic system than it can bear → Cette politiquemet le systèmeéconomique à troprudeépreuve.; [+ economy, finances] → grever qch
to put considerable strain on sth → peser d'un poidsconsidérable sur qch
to be under strain [person] → être sous pression
He's been under a lot of strain → Il a étésoumis à une pressionimportante.
to be a strain → être éprouvant(e)
It was a strain → C'était éprouvant.
to suffer from strain → être stressé(e)
to strain one's ears → tendre l'oreille
I strained my back → je me suis fait mal au dos
to strain one's eyes (= tire) → se fatiguer les yeux
to strain to hear sth → s'efforcer d'entendre qch
to strain to see sth → s'efforcer devoir qch
to strain at the leash [dog] → tirer sur sa laisse
strain
1nstrain
2nstrain
1[streɪn]1.nto take the strain off sth → ridurre la tensione di (or la sollecitazione su) qc
the bridge is showing signs of strain → il pontemostrasegni di deformazione
the rope broke under the strain → la corda si è spezzataa causa della tensione
she's under a lot of strain → è molto tesa, è sotto pressione
I can't stand the strain → non resisto, non ce la faccio più
the strains of modern life → il logorio della vitamoderna
to put a great strain on (marriage, friendship) → mettere a duraprova (person, savings, budget) → pesare molto su
he continued in that strain (fig) → e continuò su questo tono
don't strain yourself! (also) (iro) → non affaticarti troppo!
to strain the truth → deformare la verità
to strain every nerve to do sth → fare ogni sforzo per fare qc
to strain one's voice → sforzare la voce
to strain one's ears → aguzzare le orecchie
to strain (one's eyes) to see sth → aguzzare la vista per vedere qc
to strain against (ropes, bars) → far forza contro
strain
2[streɪn]n (breed) → razza; (lineage) → stirpef; (of virus) → tipo; (streak, trace) → tendenzastrain1
(strein) verbstrain2
(strein) nounstrain
→ جُهْد, يُجْهِدُ nápor, přepínat belastning, lægge pres påbelasten, Belastungένταση, καταπονώtensar, tensión rasittaa, rasituseffort, s’efforcer napor, naprezati sesforzare, tensione 極度の緊張, 緊張させる 긴장시키다, 부담belasten, spanningbelaste, belastningnapiąć, napięciepressionar, tensãoрастягивать, растяжение anstränga sig, påfrestning ความตึงเครียด, ทำงานหนักเกินไปstres, strese sokmak làm căng thẳng, sự căng thẳng使超过负荷, 负担strain
strain
n (stress) estrés m, presión f; (of bacteria, etc.) cepa; (muscle, tendon) distensión f (muscular), tirón m (muscular), desgarro parcial de un músculo o tendón debido a uso excesivo o incorrecto; vt (a muscle or tendon) sufrir una distensión (muscular), sufrir un tirón (muscular), lastimar por uso excesivo o incorrecto (un músculo o un tendón); (one's eyes, one's voice) forzar (la vista, la voz); (urine for stones) colar (la orina para piedras); vi es-forzarse, hacer un gran esfuerzo; (at stool) pujar (para defecar)Want to thank TFD for its existence? Tell a friend about us, add a link to this page, or visit the webmaster's page for free fun content.
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