Lecture 4 strain gauge tutorial free download as powerpoint presentation. Unbonded strain gages, where the wire is free, are rarely used because of their limited frequency range and lack of sensitivity. The most widely used pressure and force sensitive transducer is the strain gauge. Explore strain gauge with free download of seminar report and ppt in pdf and doc format. The strain gauge can be protected by the application of a certain varnish. Also explore the seminar topics paper on strain gauge with abstract or synopsis, documentation on. Strain can be measured using various types of devices classified.
For the obtained results, draw mohrs circle of strain. The strain gauge set mechanically measures strain in masonrytype materials or in structural components under load, relative displacements in structures, opening or closing of cracks, shrinkage of concrete block during drying, and similar applications. Strain what conditions static dynamic duration frequency measuring method. Sensitivity of a thin metallic conductor to strain 3. Karl hoffmann an introduction to stress analysis and transducer design using strain gauges. Most strain gauges are smaller than a postage stamp, and they look. If the nominal resistance of the strain gauge is designated as rg, then the straininduced change in resistance. Ramesh is not responsible for any direct or indirect. The corrected strains calculated in equations 12, and 14 are plotted on the horizontal axis in figure 5 and designated with a 1. A strain gauge is a device that is used to measure the strain at the surface of a structure. Alternatively, strain gauge conductors may be thin strips of metallic film deposited on a nonconducting substrate material called the carrier. Microstrain is a dimensionless value labeled microstrain strain, e. Strain is a nondimensional value that represents the change of length of a material relative to its initial length. When external forces are applied to a stationary object, stress and strain are the result.
Depending on the arrangement of strain gauges, strain rosettes are classified in to. Electrical conductor possesses resistance based on the relationship r. Strain gages and rosettes study notes for mechanical engineering. When an external force is applied on an object, due to which there is a deformation occurs in the shape of the object. Other types of strain gages are acoustic, capacitive, inductive, mechanical, optical, piezoresistive, and semiconductive. A strain gauge sometimes refered to as a strain gage is a sensor whose resistance varies with applied force.
Strain gaugetransducer,sensor,wheatstone bridge,electrical. Download free sample and get upto 37% off on mrprental. Which strain gauge is the right one for your application. This deformation in the shape is both compressive or tensile is called strain, and it is measured by the strain gauge. The latter form of strain gauge is represented in the previous illustration. If the nominal resistance of the strain gauge is designated as rg, then the strain induced change in resistance. Alok barua, department of electrical engineering,iit kharagpur. Half bridge circuit thus, consider the cantilever beam specimen pasted with four strain gauges subjected to transverse loading. The free surface on which the strain rosette is attached is actually in a state of plane stress, while the formulas used above are for plane strain. The backing is then bonded with an adhesive to the test specimen.
Installation of an strain gauges howto installa strain gauges. As compared to lvdt this transducer has short body length and is free from. Hbms extensive strain gauge catalog provides 100 pages of information about our extensive choice of strain gauges ranging from standard strain gauges for experimental stress analysis through special strain gauges to strain gauge accessories you can be sure that you will get the. Strain gauge definition of strain gauge by the free dictionary. Most strain gauges are smaller than a postage stamp, and they look something like this. Strain gages structure of strain gages there are many types of strain gages. Aug 02, 2017 the free surface on which the strain rosette is attached is actually in a state of plane stress, while the formulas used above are for plane strain. Fundamentals of industrial instrumentation by alok barua pdf thank you unquestionably much for downloading fundamentals of industrial instrumentation by alok you have knowledge that. Pressure mpa strain gauge1 strain gauge 2 strain gauge 3 strain gauge 4 strain gauge 5 strain gauge 6 points for discussion 1. Lvdts find uses in modern machinetool, robotics, avionics, and computerized manufacturing. Hbms extensive strain gauge catalog provides 100 pages of information about our extensive choice of strain gauges. Among strain gages, an electric resistance wire strain gage has the advantages of lower cost and being an established product. Positional sensors linear variable differential transformers lvdts the linear variable differential transformer lvdt is an accurate and reliable method for.
What are strain gauge passive transducerbonded strain gaugetransducers. Measurement of stress due to bending using a strain gage. Discuss the reasons for deviation of experimental results with that of theory if there any. Strain gauges are used to determine or verify component or structure stresses, or by manufacturers of load cells, pressure and torque transducers, etc.
Gauge factor needs to be found experimentally in strain gauge. The wiring and the strain gauge itself will have a nonzero temperature coefficient of resistance. Changes in temperature will cause the strain gauge itself to expand or contract, independent of any. The gauge consists of a thin conductive metal foil grid pattern that is mounted on a flexible backing. The principle of the strain gauge is based on the resistive properties of electrical conductors. Aug 08, 2008 lecture series on industrial instrumentation by prof. Strain can be measured using various types of devices classified depending upon their principle of operation. Strain rosette can be defined as the arrangement of strain gauges in three arbitrary directions. The mohrs strain circle can be drawn as per the procedure described earlier. Installation of an strain gauges measured quantity.
However, the temperature effect is the same in all the strain gauges. Among them, a universal strain gage has a structure such that a gridshaped sensing element of thin metallic resistive foil 3 to. Therefore, if we replace r4 in figure 3 with an active strain gauge, any changes in the strain gauge resistance will unbalance the bridge and produce a nonzero output voltage. Login for those who have not completed hp support registration if this is your first time to visit or if you have not completed hp support registration, please continue by clicking on the button below. What is a wheatstone bridge and other strain gauges circuits.
Strain gauge is a passive transducer that converts a mechanical elongation or displacement produced due to a force into its corresponding change in resistance r, inductance l, or. Transducers definition of transducers classification. Board strain can be identified and measured through tools such as. Kinematics of serial robots 4 introduction, direct and inverse kinematics problems, examples of kinematics of common serial manipulators, workspace of a serial robot, inverse kinematics of constrained and redundant robots, tractrix based approach for fixed and free. Strain gage market analysis 2011 to 2016 by cost and market profit forecasts to 2021 the strain gage industry report titled global and chinese strain gage industry, 20112021 market research report is a. Strain gauge 5 strain gauge 6 closed cylinder arrangement sl. Standard resistance are 120 and 350 ohms, whereas 500, and 3000 ohms are for special purpose gauges. According to beam theory, the top surface gauges 1, 3 is in tension and the bottom surface gauges 2, 4 is in compression. Strain gauge how conditions stationary mobile surrounding.
These strain gauges are used to measure the normal strain in those three directions. Strain gauge preparation by sticking a short length of adhesive tape along the upper face of the gauge it may be picked up from a flat clean surface. The due date for submitting this assignment has passed. Strain gage market analysis 2011 to 2016 by cost and market profit forecasts to 2021 the strain gage industry report titled global and chinese strain gage industry, 20112021 market research report is a professional and indepth study on the current state of the global strain gage industry with a focus on the chinese market. Therefore, the strain transform in the free surface plane can be applied. The materials of the strain gauge itself have a nonzero coefficient of thermal expansion. Fundamentals of industrial instrumentation by alok barua pdf. Resistance strain gauge the change in value of resistance of metal semiconductor due to. Jan 03, 2014 the materials of the strain gauge itself have a nonzero coefficient of thermal expansion. Gauge length defnition gauge length of a strain gauge is the active or strain sensitive length of the grid. However, the normal direction of the free surface is indeed a principal axis for strain. Strain gauge seminar report, ppt, pdf for mechanical.
Strain gauge and rosettes a strain gauge is a device which is used to measure strain deformation on an object subjected to forces. Among them, a universal strain gage has a structure such that a gridshaped sensing element of thin metallic resistive foil 3 to 6m thick is put on a base of thin plastic film 15 to 16 m thick and is laminated with a thin film. Hbms extensive strain gauge catalog provides 100 pages of information about our. Positional sensors linear variable differential transformers lvdts the linear variable differential transformer lvdt is an accurate and reliable method for measuring linear distance. Fundamentals of industrial instrumentation by alok barua pdf thank you unquestionably much for downloading fundamentals of industrial instrumentation by alok.
Name different methods for force measurement with strain gages. Definition a strain gauge is an example of passive transducer that converts a mechanical displacement into a change of resistance. The report provides key statistics on the market status of the. Steps in fitting a strain gauge to a surface 7 connect the lead wires. Temperature effects in strain measurement data acquisition. Changes in temperature will cause the strain gauge itself to expand or contract, independent of any strain inthe part to which it is attached. Pdf using strain gages to measure both strain and temperature. The resultant force p 2 of the internal pressure is a force equal to pr. What are strain gauge passive transducerbonded strain gauge transducers. What is strain gauge types of strain gauges what is strain gauge. The construction of mohrs circle for strain starts with drawing horizontal normal strain. Lecture series on industrial instrumentation by prof.
The gauge consists of a thin conductive metal foil grid pattern that is mounted on a flexible backing see figure 5. Also explore the seminar topics paper on strain gauge with abstract or synopsis, documentation on advantages and disadvantages, base paper presentation slides for ieee final year mechanical engineering me or production automobile students for the year 2019 2020. The value of the resistance r necessary to simulate the output due to a mechanical strain e at the active gauge is found from the approximate formula where r is the resistance of the arm to be shunted and k is the gauge factor of the active strain gauge. The value of the resistance r necessary to simulate the output due to a mechanical strain e at the active gauge is found from the approximate formula where r is the resistance of the arm to be.