wind pressure

The structural design of glasshouses must provide for safety from wind damage while permitting maximum light transmission to the crop. A literature review of codes of practice, recommendations and data concerning wind loads on buildings showed several different procedures for describing the wind speed near the ground and predicting design pressures on low profile buildings.

A major study of wind loads on low-rise buildings has culminated in a relatively simple formulation for the wind loading for such structures. These proposed load requirements reflect many important aspects of the wind action, such as the predominance of unsteady loads, the reduction in effective loading with increased tributary area, and the provision of separate sets of loads, intended to be used together, for design of primary structural members.

Reports investigation of mean and fluctuating pressure inside buildings, induced by wind using boundary layer wind tunnel and computer simulation techniques. Mean and root-mean-square fluctuating internal pressure coefficients were both found to be monotonic functions of the ratio of windward to leeward opening areas.< The case of a single windward opening was treated as a damped Helmholtz resonator.

Reviews the important variables which need to be known when analyzing wind loads on low buildings. These include reference height, roof angle, end zones, internal pressures and openings, surrounding terrain and buildings.

Describes a covariance integration method for the determination of fluctuating overall structural loads due to wind and their effects on low rise buildings. The required aerodynamic information can be obtained from boundary-layer wind tunnel tests: static structural influence coefficients are also required. Themethod is an alternative to the direct on-line weighting technique, but is less demanding on wind tunnel instrumentation and data acquisition facilities. To obtain peak values, Gaussian probability distributions have been assumedfor the loads or their effects.

Gives a brief historical review of the development of wind engineering as a discipline. Discusses the simulation of wind loads on buildings, the development of boundary layer wind tunnels and problems in modelling the natural wind. Describes modelling of the aerolastic behaviour of buildings andof stack gas diffusion. Describes instrumentation and measurement techniques. Indicates areas requiring further development.

Describes the first stage of an investigation designed to simulate in a wind tunnel the full scale wind pressure measurements made by the Building Research Establishment on the Aylesbury test house. Describes in detail the wind tunnel, instrumentation, measurement techniques and experimental procedures. Discusses the problems of simulating natural wind.< Discusses the results of measurements of mean pressure coefficients. Compares results with full scale measurements and results of a wind tunnel simulation made at the University of Bristol.

Describes some of the problems encountered when the full-scale wind pressure measuring system was set up in an experimental building at the University of Hong Kong. Discusses effects such as excessive damping caused by the air trapped in the pressure- balancing tubings, and the interference between transducers. Describes modifications of the measuring system to overcome these problems.

Reports wind tunnel measurements of the wind-induced internal pressures of models of low-rise buildings of different geometry and internal volume. Three different uniform porosities (0.0 0.5 and 3.0% of the total surface area) have been examined in combination with openings in a wall ranging from 0 to 100% of that wall's area. Two terrain roughnesses were used corresponding to open country and suburban regions.< Finds that internal pressures are variable but generally lower than local external pressures.

Reports study of wind and rain over fifteen years and gives table of results. Reports measurements of wind pressure and driving rain on buildings. Discusses laboratory measurements of the tightness of facade elements under pressures of up to 50 Pa. and with temperature differences of -40 to +30 deg.C. across the facade. Describes pressurization of buildings and gives results of measurements in test dwellings. Discusses movement of joints in buildings and describes measurement of this movement.< Discusses permeability of both flat and sloping roofs.