Showing papers in "Strain in 1989"
TL;DR: In this article, the residual stress measurements were made close to the toe of each fillet weld on a load carrying cruciform welded specimen by the hole drilling technique using a standard milling guide with high speed air turbine in conjunction with bonded resistance strain gauge rosettes.
Abstract: Residual stress measurements were made close to the toe of each fillet weld on a load carrying cruciform welded specimen by the hole drilling technique A standard milling guide with high speed air turbine was used in conjunction with bonded resistance strain gauge rosettes Experimental calibrations of the method were conducted under known uniform uniaxial tension loads
A simple incremental drilling technique was used to determine the stress gradient with hole depth Measurements were also made both at zero load and known tensile loads in order to study the interaction between residual stresses and the applied loads
26 citations
TL;DR: In this article, the use of a uniformly stressed component for the calibration of SPATE (Stress Pattern Analysis by Thermal Emission) was discussed, and the results for sinusoidal loading on a carbon steel were compared with a theoretical prediction based upon material properties and instrument characteristics.
Abstract: For the past five years the National Engineering Laboratory (NEL) has been engaged in a research programme investigating the applications of thermoelastic stress analysis to engineering structures. This paper discusses the use of a uniformly stressed component for the calibration of SPATE (Stress Pattern Analysis by Thermal Emission). Experimental results for sinusoidal loading on a carbon steel are compared with a theoretical prediction based upon material properties and instrument characteristics. A calibration technique which is suitable for the measurement of quantitative stresses under random loading, including modal behaviour, is also described.
8 citations
TL;DR: In this article, a new technique called TERSA (Thermal Evaluation for Residual Stress Analysis) is proposed for non-contacting and non-destructive determination of static and residual stresses in engineering components, assemblies and structures.
Abstract: This paper outlines a completely new technique which could provide the basis of an instrument for the non-contacting and non-destructive determination of static and residual stresses in engineering components, assemblies and structures. The method has been given the acronym of TERSA, standing for Thermal Evaluation for Residual Stress Analysis and would be applicable to a range of metals, both ferrous and non-ferrous and also to plastics. Some experimental work is described and results are presented which confirm the principle of the proposal.
5 citations
TL;DR: In this paper, the effects of the uncertainties associated with the apparent strain and gauge factor data, given by the manufacturer, in the evaluation of principal strains are examined, and theoretical analysis points out the relevance of the effects caused.
Abstract: The effects of the uncertainties associated ith the apparent strain and gauge factor data, given by the manufacturer, in the evaluation of principal strains are examined. Principal strains are obtained by a reduction of the strains measured ith electrical resistance strain gauge rectangular or delta rosettes. The theoretical analysis points out the relevance of the effects caused.
5 citations
TL;DR: The earliest developments in the use of electrical strain gauges as a means of quantifying the measurement of stress in materials are recalled by the author, whose own involvement was associated with the early developments in mechanised production of strain gauge as mentioned in this paper.
Abstract: The earliest developments in the use of electrical strain gauges as a means of quantifying the measurement of stress in materials are recalled by the author, whose own involvement was associated with the early developments in the mechanised production of strain gauges. The manufacture of batch quantitities is vividly recounted following the realisation that strain gauges would lend themselves to commercial exploitation.
4 citations
TL;DR: In this article, an experimental device able to detect the load eccentricity in helical compression springs is described, and the theory underlying the resolution of measured bending strains of the apparatus into effective load eccentricities is discussed.
Abstract: An experimental device able to detect the load eccentricity in helical compression springs is described. The theory underlying the resolution of measured bending strains of the apparatus into effective load eccentricity is discussed. Laboratory results are offered for heavy duty springs and compared to theoretical estimates retrieved from the literature.
3 citations
Journal Article•
TL;DR: In this paper, the design of a new transducer of the LVDT (linear variable differential transformer) type was described, where two separate pot and disc assemblies were employed, with each assembly consisting of half the primary winding and one secondary winding.
Abstract: This article described the design of a new transducer of the LVDT (linear variable differential transformer) type. Instead of the traditional configuration, with three coils all enclosed by the same magnetic circuit, two separate pot and disc assemblies were employed, with each assembly consisting of half the primary winding and one secondary winding. These were mechanically coupled so that the air gap of one assembly was reduced while that of the other increased. Electronically the two halves of the primary were connected in series addition and the two secondaries in series opposition. Mechanically the two halves of the device could be physically remote from each other provided that the mechanical coupling between them was completely rigid. Full details of the experimental model were provided in this paper, as was the method to set the air gap using a travelling microscope.
3 citations
TL;DR: In this paper, a simple formal method of evaluating principal stresses and directions using eigenvalues and eigenvectors of the stress matrix is presented, which is equally applicable to 2-d and 3-d stress systems and does much to eliminate any risk of undetected errors in calculation or mistakes in assigning a principal stress to its corresponding direction.
Abstract: A simple formal method of evaluating principal stresses and directions using eigenvalues and eigenvectors of the stress matrix is presented. The method is equally applicable to 2–d and 3–d stress systems and does much to eliminate any risk of undetected errors in calculation or mistakes in assigning a principal stress to its corresponding direction. The method is extended to analysis of the 45dstrain gauge rosette.
3 citations
TL;DR: In this paper, a semi-rigid joint used extensively in the storage and materials handling industry is tested using automated methods of routine testing, and the results show that the test data required by companies to present to external checking authorities increases.
Abstract: As the amount of test data required by companies to present to external checking authorities increases, automated methods of routine testing are becoming important. This paper outlines one such procedure adopted for the testing of a semi-rigid joint used extensively in the storage and materials handling industry.
2 citations
TL;DR: The British Society for Strain Measurement (BSSM) has taken initiatives since 1977, to try to raise the standards of validation of competence in testing and analysis particularly in the areas of stress and strain measurement and analysis as mentioned in this paper.
Abstract: Standards, testing and certification are major topics of discussion in relation to the European single market in 1992. The British Society for Strain Measurement has taken initiatives since 1977, to try to raise the standards of validation of competence in testing and analysis particularly in the areas of stress and strain measurement and analysis. This paper sets out some of the current thinking of the BSSM, in an attempt to obtain wider support for and participation in, what it considered to be one of the vital approaches to improved product quality, performance, safety and reliability.
1 citations
TL;DR: In this paper, a technique for the clamping of metallic foil strain gauges during epoxy adhesion bonding to non-porous surfaces is described, where the gauge is conformed to the surface using self-adhesive tape and the workpiece placed in a pressurised environment for the duration of cure.
Abstract: A technique is described for the clamping of metallic foil strain gauges during epoxy adhesion bonding to non -porous surfaces. Following application of the uncured adhesive, the gauge is conformed to the surface using self-adhesive tape and the workpiece placed in a pressurised environment for the duration of cure. The pnematically derived clamping pressure is transmitted directly to the glue line, and is equal to the pressure within the containment vessel. Since the clamping pressure is both uniform over the strain gauge area, and readily reproducible between installations, it is possible to produce consistent gauge performance. The technique may offer time and cost advantages over classical clamping methods where gauges are installed on small, intricate, or batch components in stress analysis and transducer applications.
TL;DR: In this paper, the authors pointed out that it may be inaccurate thinking of the nature of cold (logarithmic) creep -i.e. creep hich may be observed in most steels at room temperature (20dC).
Abstract: This note is aimed at highlighting hat may be inaccurate thinking of the nature of cold (logarithmic) creep - i.e. creep hich may be observed in most steels at room temperature (20dC). There is a dearth of information on this topic although engineers have come to regard cold creep as a ‘time dependent plastic’ deformation. As such it is assumed that the assumptions of plasticity are obeyed during the creep process.
TL;DR: In this article, an extensive analysis on strand behaviour and the lubricant effect in strain fields was examined, using electrical resistance strain gauges, and the results obtained, by loading the unlubricated and lubricated sample both statically and quasi-statically, showed relevant effects caused by different contact loads developed among the wires.
Abstract: As a part of an extensive analysis on strand behaviour the lubricant effect in strain fields was examined. The strains were measured by using electrical resistance strain gauges. The results obtained, by loading the unlubricated and lubricated sample both statically and quasi-statically, showed relevant effects caused by different contact loads developed among the wires. By examining the strains measured during the severing of one helical wire the inapplicability to the strands of one Italian regulation relative to wire ropes, was also confirmed.
TL;DR: In this paper, an analysis of the transient bending and shear stresses set up in the drive shaft of an 11 W ring main switch unit manufactured by South Wales Switchgear Ltd.
Abstract: An analysis has been made of the transient bending and shear stresses set up in the drive shaft of an 11 W ring main switch unit manufactured by South Wales Switchgear Ltd. The analysis compares theoretical bending and shear stress plots along the main shaft with experimental values obtained from electrical resistance strain gauges.