ISSN:0039-2103    

DOI:10.1111/j.1475-1305.1981.tb00353.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

ISSN:0039-2103    

DOI:10.1111/j.1475-1305.1981.tb00354.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

The principles of operation and the experimental equipment used during an investigation into the role of percolating water within concrete and rock, have been outlined. Attention has been drawn to a problem of measuring a friction force which, if not resolved, would have compromised the investigation. The design requirements of a simple acoustic tensile load cell, capable of resolving the problem, are listed with details of its design, construction and satisfactory performance.

ISSN:0039-2103    

DOI:10.1111/j.1475-1305.1981.tb00355.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

The mechanism by which load is transferred from a discontinuous fibre to surrounding unbroken fibres has been examined in some detail using two dimensional photoelastic models in which the applied load is aligned with the fibre axes. The gap in the broken fibre is assumed to have occurred during fabrication and is thus filled with the matrix material. Three different end gap configurations have been analysed and it is concluded that, for all practical purposes, the disturbance due to the broken fibre does not extend beyond the immediately adjacent fibres. Substantial shear stresses are developed in the matrix for some distance along the fibre from the discontinuity with a consequent early transfer of load. Paradoxically, this effect is not accompanied by the development of reduced maximum stresses at the broken fibre tip for any of the configurations included in these tests.

ISSN:0039-2103    

DOI:10.1111/j.1475-1305.1981.tb00356.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

A problem in the area of the investigation of structural behaviour is the elastic plastic deformation in the vicinity of disturbances like crack tips. Intrinsically the deformation can be measured by measuring the deformation of a grid on the surface in the vicinity of the disturbance. The paper describes a new simple grid system. The grid system consists of the picture layer of a selected photo printing paper. The picture layer is pealed off its carrier and is bonded on the polished specimen surface by means of a fresh cyanoacrylate cement. This system can sustain deformations up to 40% and has a very good contrast. A square grid is bonded on the local surface, the grid is photographed at several load values and later the negatives are magnified and read by means of an image analyser.A relevant question arising in the investigation of the buckling of a metal sheet with Z‐section stringers is how the sheet and the stringers deform relative to each other. This is answered by bonding drinking straws perpendicular to the surface of the specimen at several locations. When the surface rotates out of plane the free ends of the straws show relatively large displacements which have been recorded by means of a 35 mm film camera. The free ends of the straws have been provided with small white disks with central black dots. Films are read by means of an image analyser. Very small differences in rotations between the stringer heads and the sheet can be detected before the specimen collapse

ISSN:0039-2103    

DOI:10.1111/j.1475-1305.1981.tb00357.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

This paper describes the calibration of commercial accelerometers with mass load by laser interferometry at frequencies ranging from 2 kHz to 10 kHz. It is shown by experiment that the effect of mass load on the frequency response of commercial accelerometers with inverted centre mounted compression design is negligible. The comparison method adopted by some foreign companies has been analysed and the relative motion between the top of the mass load and the upper surface of a commercial accelerometer has been measured, thus explaining the obvious errors in frequency response curves obtained by using the comparison method.

ISSN:0039-2103    

DOI:10.1111/j.1475-1305.1981.tb00358.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

ISSN:0039-2103    

DOI:10.1111/j.1475-1305.1981.tb00359.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

Book reviewed in this article:Creep of engineering materials and structures Edited by G. Bernasconi and G. PiattiBackground to buckling, by H. G. Allen and P. S. BulsonAn Introduction to Finite Element Computations. by E. Hinton and D. R. J. Owen

ISSN:0039-2103    

DOI:10.1111/j.1475-1305.1981.tb00360.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

ISSN:0039-2103    

DOI:10.1111/j.1475-1305.1981.tb00361.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

ISSN:0039-2103    

DOI:10.1111/j.1475-1305.1981.tb00362.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY