ISSN:0039-2103    

DOI:10.1111/j.1475-1305.1996.tb00994.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

AbstractFour steel specimens were equipped with “duplex nances”, a recently proposed transducer based on two different electrical resistance strain gauges, capable of correcting the effects induced by temperature. The examined innovative transducer, in comparison with traditional strain measuring systems, has the advantage of utilising two strain gauge channels of the same type, which significantly simplifies automatic measuring systems. The specimens were subjected to temperature and strain field variations in the ranges of=30–150°Cand=100–700μm/m respectively The temperature and strain values obtained from the duplex gauges were compared with those measured by means of traditional methodology, i.e. a strain gauge and a the

ISSN:0039-2103    

DOI:10.1111/j.1475-1305.1996.tb00995.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

AbstractIn stress measurement where it is difficult or impossible to access the inside surface of the structure, “double deck” (DD) or “sandwich” bending strain gauges can be used to measure both the membrane and bending strains. A DD gauge consists of a pair of constituent foil gauges which are bonded on the upper and lower surfaces of a plastic base or filling. It is mounted on the external surface of the test specimen to measure the external surface strain, and by extrapolation, the internal surface strain of the. specimen. The. sensitivity of the DD bending gauge increases when the separation between the pair of constituent foil gauges increases. However, this also increases the stiffness of the whole gauge. If the stiffness of the DD gauge is significant compared with that of the plate to which it is attached, the presence of the gauge may cause significant changes in local stiffness and result in errors of strain interpretation. This study is presented in two papers. Part I, appeared in the Feburary 1996 issue of Strain, presented an approximate analytical solution for the local stiffening effect of a DD gauge, and quantifies the errors in the strain measurement. Part 2 (this paper) presents the verification of the. solution using a three‐dimensional finite element calculation, a parametric study and a correction method that can be applied easily. The extrapolation errors due to the stiffening effect and random reading noises are also explored. The figure and equation numbers in this part are continuedfrom Part 1, but the reference numbering is specific

ISSN:0039-2103    

DOI:10.1111/j.1475-1305.1996.tb00996.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

AbstractThe shearographic interferometry is employed as a nondestructive full field, optical testing and measuring method without contact. Fringes of constant strain (so called isotase, tasis (Greek)=strain) can he observed in real time on the surface of the investigated machine parts and structures of any material and are represented by the shearogram. Using shearography two states of “deformation are recorded by doubly exposing a Holotesl film in an ordinary camera or stored by an electronic image processing system. In the lens of the camera a shearing element inside or outside the focus is integrated or the lateral Michelson shearing interferometer is used. Rigid body motions of the object are not recorded. Local deformation irregularities caused by a defect under or on the surface of the specimen create, strain concentrations; the homogeneous surrounding is poorly superimposed by an interference pattern. The shearogram shows dark and bright fringes which are the functions of the displacement derivative. The holographic interferometry measures the out of plane deformations directly. Terms of the out of plane strain can be determined by the shearographic method as well as the in plane strain fringes which are described in the followin

ISSN:0039-2103    

DOI:10.1111/j.1475-1305.1996.tb00997.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

AbstractA new moiré method is proposed to map partial slope, partial curvature and twist curvature contours of laterally loaded specularly reflecting plate models. Converging HeNe laser light is diffracted by a lens plane cross grating, different combinations of orders are selectively permitted through the Fourier transform plane and collimated to illuminate the plate model. This technique eliminates the difficulties involved in Fourier filtering in the imaging optics, thereby extending the reflection moiré’ interferomelry to general plate structures and loading. The slope contours are obtained still by double expos

ISSN:0039-2103    

DOI:10.1111/j.1475-1305.1996.tb00998.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

ISSN:0039-2103    

DOI:10.1111/j.1475-1305.1996.tb00999.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

ISSN:0039-2103    

DOI:10.1111/j.1475-1305.1996.tb01000.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

ISSN:0039-2103    

DOI:10.1111/j.1475-1305.1996.tb01001.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

ISSN:0039-2103    

DOI:10.1111/j.1475-1305.1996.tb01002.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

ISSN:0039-2103    

DOI:10.1111/j.1475-1305.1996.tb01003.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY