摘要:

The authors previously established that an initially flat rectangular steel plate, clamped on all four edges, displays three modes of behaviour as the intensity of a distributed transverse load increases: elastic flexural-membrane action, inelastic flexural-membrane action, and inelastic-membrane action.For a long narrow plate, elastic flexural-membrane action exists up to the load at which yielding of the extreme fibres along the long edges occurs. Subsequent plastic hinge formation along the long edges reduces the stiffness. The second stage ends with complete yielding in tension along the long edges. From this point onward, the plate acts essentially as a membrane straining inelastically as yielding gradually progresses from both edges toward the centre. A lower bound to this behaviour is obtained by assuming that Poisson's ratio is the elastic value and the maximum membrane stress is the yield stress. A higher lower bound is obtained using the plastic value of Poisson's ratio. The load–deflection curve gradually moves from the lower value to the higher and, because the edge forces can exceed yield, will finally exceed the latter, as confirmed by tests.A finite element program modelling plane stress conditions, the inelastic Poisson's ratio, and the stress–strain behaviour to failure gave a load–deflection response closely following the three predicted regions of behaviour. Two failure criteria have been established: a limiting tensile strain due to bending and tension at the edge and the shear resistance there. The behaviour and failure loads have been confirmed by two tests. Strain measurements taken during the tests substantiate, in general, the predicted behaviour.Implications of using the ultimate strength of plates for the design of offshore structures for oil exploration and production in the Arctic are presented.Key words: deflection, design, finite elements, inelastic, membrane, plates, steel, strains, stresses, transverse load, ultimate strength.

ISSN:0315-1468    

DOI:10.1139/l86-011

出版商:NRC Research Press    

年代:1986

数据来源: NRC

摘要:

A critical review of the problems encountered in attempting to quantify flood damage is used to demonstrate inconsistencies, omissions, and variabilities among previous studies and procedures. A reasonable procedure for updating residential depth – damage data from previous studies is shown to involve use of the all-items consumer price index. Recommended strategies for flood damage estimation involve calibration of synthetic stage – damage data to observed flood damage data.

ISSN:0315-1468    

DOI:10.1139/l86-012

出版商:NRC Research Press    

年代:1986

数据来源: NRC

摘要:

The buildup of surface pollutants has been shown to be a controlling factor in the quality of storm water runoff. In industrial areas particularly, atmospheric fallout is an important component of surface pollutant loadings. Storm water runoff models presently in use do not consider the physics of atmospheric dustfall.Industries, vehicle exhausts, and blowing of wind over unprotected surfaces all introduce pollutants to the atmosphere. Redistribution of this material on the ground depends on local topography and prevailing meteorological conditions. The location of the industrial areas; the direction, velocity, and duration of wind; total precipitation; and source concentrations are important parameters in the prediction of atmospheric dustfall. The paper describes the physical processes of atmospheric fallout that are relevant to water quality modelling. A new model, called ATMDST, to predict dustfall on individual subcatchments in a metropolitan area using prevailing meteorological conditions is developed based on statistical methods. Results from average, one-variable and two-variable linear regression models were statistically compared with observed data. Finally, ATMDST is interfaced with the storm water management model version 3 (SWMM3) to compute runoff water quality. The model is applied to Hamilton, Ontario.Key words: atmospheric dustfall, air pollution, urban runoff, water quality, pollutant buildup, environmental modelling.

ISSN:0315-1468    

DOI:10.1139/l86-013

出版商:NRC Research Press    

年代:1986

数据来源: NRC

摘要:

The paper summarizes the results of push-off tests conducted on 42 end stub assemblages. Written for conventional composite construction, the current Canadian Standards Association (CSA) standard on stud connectors offers little guidance for stub–girder design. A stud spacing of four times the stud diameter (the CSA requirement) does not appear to be adequate for a full development of the potential shear capacity of a stud connector in the stub–girder system. The required minimum stud spacing appears to be between five and six times the stud diameter for the case of 13 mm studs. Moreover, the CSA-recommended shear capacity of stud connector should be reduced to reflect the effect of prying forces. A modification factor of 0.9 is suggested for a 13 mm diameter stud connector. Test results for specimens with 19 mm studs indicated a further decrease in the shear capacity. However, a definite recommendation is postponed pending further tests.In addition to prying forces, stud configuration and spacing and the amount and location of transverse reinforcement must also be taken into account in determining the shear capacity of a stud connector. For a connection with 13 mm studs arranged in a single row, a reduction factor equal to stud spacing divided by six times the stud diameter is suggested when the stud spacing is less than six times the stud diameter. For a connection with staggered studs, the corresponding factor is obtained by dividing the stud spacing by five times the stud diameter when the stud spacing is less than five times the stud diameter.Key words: headed stud, shear capacity, minimum stud spacing, prying force.

ISSN:0315-1468    

DOI:10.1139/l86-014

出版商:NRC Research Press    

年代:1986

数据来源: NRC

ISSN:0315-1468    

DOI:10.1139/l86-015

出版商:NRC Research Press    

年代:1986

数据来源: NRC

ISSN:0315-1468    

DOI:10.1139/l86-016

出版商:NRC Research Press    

年代:1986

数据来源: NRC

ISSN:0315-1468    

DOI:10.1139/l86-018

出版商:NRC Research Press    

年代:1986

数据来源: NRC

ISSN:0315-1468    

DOI:10.1139/l86-019

出版商:NRC Research Press    

年代:1986

数据来源: NRC