ISSN:0039-2103    

DOI:10.1111/j.1475-1305.1996.tb00984.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

AbstractGeometric imperfections, commonly in the form of depressions at the circumferential welds, are present in most metal silo structures and can greatly reduce the structure's buckling strength. These imperfections sure close to axisymmetric in form. This paper describes the measurement system which was developed for an experimental study of this phenomena. Computer controlled steppennotors for both Hie circumferential and longitudinal travel of the measurement carriage provided a precise and repeatable traverse of the specimen. A laser displacement meter, which is capable of high speed, non‐contact measurement and has a resolution of 0.5 microns, was controlled synchronously with the steppennotors to provide a very accurate three‐dimensional measurement system. Both the initial geometrically imperfect shape and the progressive growth of deformations during loading were accurately measu

ISSN:0039-2103    

DOI:10.1111/j.1475-1305.1996.tb00985.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

AbstractThis paper presents a whole field laser speckle method for the measurement of the necking zone on the surface of metallic specimens. The method employs an expanded laser beam to illuminate the test object. Diffracted images are recorded on a high resolution photographic film and subsequently filtered using point wise filtering. The intensity of the diffracted halo is measured with a photo‐sensor and the intensity distribution on the specimen yields information on the necking zone of the test object. The technique is applied to aflat tensile specimen with two circular notches at the central portion. Measured necking zone is compared with results obtained by other conventional method

ISSN:0039-2103    

DOI:10.1111/j.1475-1305.1996.tb00986.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 presents an approximate, analytical solution for the local stiffening effect of a DD gauge and quantifies the errors in the strain measurement. Part 2, to appear subsequently in Strain, will present 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 e

ISSN:0039-2103    

DOI:10.1111/j.1475-1305.1996.tb00987.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

AbstractSome aspects of the philosophy of shakedown are presented relevant to the requirement of the British pressure vessel code British Standard BS 55(X): 1994 for proof hydraulic pressure tests on vessels containing features not covered in the design rules within BS 55(X). The difficulties in achieving the objective of the test are discussed. Examples are provided from the experiences gathered from such proof hydraulic tests on over 50 commercial pressure vessels.

ISSN:0039-2103    

DOI:10.1111/j.1475-1305.1996.tb00988.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.tb00989.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.tb00990.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.tb00991.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.tb00992.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.tb00993.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY