Transverse Sensitivity Research Articles

On the measurement of transverse sensitivity of strain gauges

The influence of the transverse sensitivity factor n on errors in the measurement of strain are discussed and it is concluded that, providing the factor n is within £0015, its effect may be disregarded in all normal applications. The determination of n on a gauge factor calibration rig is considered and an analysis made of the degree of accuracy attainable.

Accounting for the transverse sensitivity of wire strain gages

Accounting for the transverse sensitivity of wire strain gages

Transverse-sensitivity errors in biaxial-stress fields

Expressions for the errors in principal stresses and stress ratio due to transverse sensitivity of the strain gauges have been determined in terms of the stress ratio. The results are also represented in the form of curves.

Accounting for the transverse sensitivity of strain-gauge transducers

The article deals with known methods of accounting for the longitudinal and transverse sensitivity of straingauges by means of coefficients k0 and κ.

Transverse sensitivity of piezoelectric accelerometric transducers

The transverse sensitivity of piezoelectric acceleration transducers is caused by the lack of coincidence between the transducer's sensitivity axis and the polarization vector of the piezoelectric plate. This fact should be taken into consideration both in the production of piezoelectric elements, and in the design of transducers and their manufacture.

Transverse sensitivity of bonded strain gages

Transverse sensitivity of strain gages usually causes unavoidable errors in two-dimensional stress analyses. Formulas have been derived for correcting these errors but involve transverse-sensitivity values which, in most cases, were not available to the user. This paper describes a method for determination of transverse-sensitivity values using a testing apparatus specially built for this purpose. Results from testing a wide variety of wire and foil strain gages are tabulated and mechanisms of the foil-gage transverse sensitivity discussed.

Transverse sensitivity in nonaligned piezoceramic vibration transducers

It is necessary to take into account in measurements made with unaligned transducers the possibility of considerable nonlinear distortions due to the doubling of harmonic oscillating frequencies which are included in the spectrum of the vibration under consideration.

Observation and evaluation of local buckling by photoelastic-strip method

A photoelastic measuring element, consisting chiefly of a strip of resin observed parallel to the surface to which it is attached, has been used in the analysis of a local-buckling problem. This strip method allows the determination of bending and membrane strain components along surface trajectories without the effect of transverse sensitivity.

Calibration Techniques Related to Vibration Pickup Use

Review of recent publications indicates that current primary laboratory-calibration methods provide sufficient accuracy for present and foreseeable future needs. An upper frequency limit for vibration measurement was first indicated by Schloss. For usual levels, this sets a lower bound to the amplitudes needed in calibration. The use of resonant systems provides means for reaching large amplitudes as they are needed. Serious errors in calibration result from transverse shake table motion. Methods for monitoring motion exist, allowing elimination of this source of error. Shakers free of transverse motion are needed urgently. Development of means for accurate measurement of the transverse sensitivity of pickups at all frequencies of interest is needed also. Full exploitation of primary calibration techniques requires suitable comparison shakers and transfer standards. Available instruments are described. The need for an adequate transfer standard pickup and the characteristics of such an instrument are discussed. To detect damage in storage and attachment or loss of accuracy caused by structural conditions or in associated circuitry, pre-use calibration checks can be performed in a number of ways. Most available methods separate the pickup from the structure and are limited in frequency and amplitude. A new instrument described by Orlacchio and Schilling allows in-place checking of entire systems over wide ranges of frequency and amplitude. Some shortcomings of the method have been indicated by Pennington and alternatives have been suggested. Published advantages, objections, and inadequacies of each method are discussed. Also, we suggest comparison of the attached pickup with a detachable, laboratory-calibrated, transfer standard, both driven in place by a pulse.

A Statistical Study of the Effects of Electric Fields on the Movements of Mammalian Sperm Cells

A micro technique has been developed to facilitate the study of electric field effects on the swimming pattern of sperm cells. The instrumentation for this technique, a micro-electrophoresis vessel, a metering motion picture projector, and a simple analog computer for data handling, are briefly described. It is shown experimentally that 1) an electric field imposed on a cell suspension acts primarily to direct the cells to the anode without appreciably changing their swimming speed, and 2) the field effects are not linear functions of field strength. It is postulated that the field effect is primarily galvanotaxis and that the cells seek a position of minimum stimulation and therefore must have a transverse sensitivity axis.