Conversely, when a conductor is

**compressed**such that it**does**not buckle, it**will**broaden and shorten, changes that decrease its electrical resistance end-to-end. From the**measured**electrical resistance of the**strain gauge**, the amount of induced stress may be inferred.Regarding this, how does strain gauges work?

The

**gauge is**attached to the object by a suitable adhesive, such as cyanoacrylate. As the object**is**deformed, the foil**is**deformed, causing its electrical resistance to change. This resistance change, usually measured using a Wheatstone bridge,**is**related to the**strain**by the quantity known as the**gauge**factor.1

## Can you get a negative strain?

When ΔL is positive, the rod is undergoing tensile

**strain**, which is also referred to as positive**strain**. When ΔL is**negative**, the rod is undergoing compressive**strain**, which is also referred to as**negative strain**.2

## What is the axial strain?

»

**Axial Strain**. An**axial**bar of length L, and cross-sectional area A, subjected to tensile force P, elongates by an amount, D. The change in length divided by the initial length is termed ENGINEERING**STRAIN**(or simply**strain**). The symbol used for engineering**strain**in most texts is e (epsilon).3

## What are the units of Microstrain?

Strain is defined as the amount of deformation per

**unit**length of an object when a load is applied. Typical values for strain are less than 0.005 inch/inch and are often expressed in**microstrain units**: Strain may be compressive or tensile and is typically measured by strain gauges.4

## What is bending strain?

The beam, or flexural member, is frequently encountered in structures and machines, and its elementary stress analysis constitutes one of the more interesting facets of mechanics of materials. A beam is a member subjected to loads applied transverse to the long dimension, causing the member to

**bend**.5

## What is the difference between lateral strain and longitudinal strain?

It is a dimensionless quantity as it is a ratio

**between**two quantities of same dimension. When a body is under load, it will extend**in the**direction of the stress (**longitudinal strain**) and contract**in the**transverse or**lateral**direction (**lateral strain**), in case of**longitudinal**tensile stress.6

## What is the meaning of lateral strain?

In continuum mechanics,

**lateral strain**, also known as transverse**strain**, is defined as the ratio of the change in diameter of a circular bar of a material due to deformation in the longitudinal direction. It is a dimensionless quantity, as it is a ratio between two quantities of the same dimension.7

## What is a strain echo?

**Strain**rate Imaging is a method in

**Echocardiography**(Medical ultrasound) for measuring regional or global deformation of the myocardium (heart muscle). Later, the regional deformation has also been available by Speckle tracking

**echocardiography**, both methods having some, but different methodological weaknesses.

8

## What is a cardiac strain?

Conclusions. Echocardiographic

**strain**imaging, also known as deformation imaging, has provided a means to objectively quantify**myocardial**mechanical function. Originally introduced as a product of TDI, speckle tracking is a more recent extension of**strain**imaging.9

## What is speckle tracking?

Two dimensional (2D)

**speckle tracking**echocardiography (STE) is a promising new imaging modality. Similar to tissue Doppler imaging (TDI), it permits offline calculation of myocardial velocities and deformation parameters such as strain and strain rate (SR).10

## What does Poisson's ratio measure?

**Poisson's ratio is**a

**measure**of the

**Poisson**effect, the phenomenon in which a material tends to expand in directions perpendicular to the direction of compression. Conversely, if the material

**is**stretched rather than compressed, it usually tends to contract in the directions transverse to the direction of stretching.

11

## What is cranial strain?

Membranous articular

**strain**, also known as**cranial strain**pattern, occurs when an articular or soft tissue restriction permits motion of the occiput and sphenoid in one direction but limits it in the opposite direction at the sphenobasilar synchondrosis.12

## What is Hooke's law for?

**Hooke's Law**. When an elastic object - such as a spring - is stretched, the increased length is called its extension. The extension of an elastic object is directly proportional to the force applied to it: F = k × e. F is the force in newtons, N.

13

## What is the definition of shear strain?

**Shear strain**is the ratio of deformation to original dimensions. In engineering,

**shear strain**is defined as the tangent of the 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.

14

## What is the symbol of strain?

Symbols and units

Description | Symbol | Name |
---|---|---|

Direct stress | σ | Sigma |

Direct strain | ε | Epsilon |

Shear stress | τ | Tau |

Young's modulus of elasticity | E |

15

## What is a tensile strain?

The stress applied to a material is the force per unit area applied to the material. The maximum stress a material can stand before it breaks is called the breaking stress or ultimate

**tensile**stress.**Tensile**means the material is under tension. The forces acting on it are trying to stretch the material.16

## What is the difference between the stress and strain?

**Stress**is a force acting on a rock per unit area.

**Stress**can cause

**strain**, if it is sufficient to overcome the strength of the object that is under

**stress**.

**Strain**is a change in shape or size resulting from applied forces (deformation). Rocks only

**strain**when placed under

**stress**.

17

## What is a tensile stress?

**Tensile stress**(or tension) is the

**stress**state leading to expansion; that is, the length of a material tends to increase in the

**tensile**direction. The volume of the material stays constant. When equal and opposite forces are applied on a body, then the

**stress**due to this force is called

**tensile stress**.

18

## What is meant by tensile stress?

**Tensile strength**is a measurement of the force required to pull something such as rope, wire, or a structural beam to the point where it breaks. The

**tensile strength**of a material is the maximum amount of

**tensile stress**that it can take before failure, for example breaking.

19

## What is a tensile test?

A

**tensile test**, also known as tension**test**, is probably the most fundamental type of mechanical**test**you can perform on material.**Tensile tests**are simple, relatively inexpensive, and fully standardized. As the material is being pulled, you will find its strength along with how much it will elongate.20

## What is a Wheatstone bridge used for?

The

**Wheatstone bridge**is**used in**two ways: (1) to measure the value of an unknown resistor by comparison to standard resistors, and (2) to detect small changes in a resistance transducer (e.g. thermistor).