Portal frame

About: Portal frame is a research topic. Over the lifetime, 1778 publications have been published within this topic receiving 7210 citations.

An Experiment to Identify the Structural Dynamics of a Portal Frame

Abstract: This paper describes the application of sequential frequency domain techniques to the estimation of mass, stiffness, and damping parameters using measured frequency response functions from a portal frame rig. The theory of the method has been described in the authors’ previous publications. A portal frame is representative of many engineering structures. It is lightly damped and may be thought of as an element of several larger structures such as bridges, transmission towers, and the steel foundations of modern power generating plant. The results offered in this paper are thus of interest to a broad range of engineering problems where it is required to obtain mathematical models in terms of physical parameters.

Multifunctional rehabilitation vehicles

Abstract: The utility model discloses a multifunctional rehabilitation vehicle, belonging to the technical field of equipment which helps the ill and the disabled rehabilitate, which provides a convenient-to-use multifunctional rehabilitation vehicle, and which is favorable for the patient to do rehabilitation exercise independently, to improve the rehabilitation effect and to alleviate burdens on the nursing staff. The utility model comprises a vehicle frame and a walking wheel; the vehicle frame is composed of an upper frame, a middle frame, a lower frame and a vertical supporter, and the back ends of the upper frame and the lower frame are respectively provided with a horizontal supporter; the upper frame is provided with a tabletop, a safety belt, a hanging ring, a fixing frame and a double-stick which is fixed on the upper frame, and the middle frame is provided with a base plate which is movably connected with the middle frame; the lower frame is provided with a chain wheel which is connected with two pedals, and the walking wheel is arranged on the lower frame; the front end of the vehicle frame is provided with a portal frame whose cross beam is a crankshaft, and the crankshaft is fixedly provided with a small chain wheel; a traction rope is tied to the crank lever of the crankshaft, and a close transmission chain is arranged between the small chain wheel and the chain wheel on the lower frame. Structures which are easy to assemble and disassemble or movable structures are mostly adopted to be the members thereof, and the utility model, which is safe and practical, alleviates burdens on the nursing staff greatly, particularly suitable for hemiplegia sufferers to exercise and rehabilitate.

Modal characteristics of structural portal frames made of mechanically joined pultruded flat hybrid composites

Abstract: The primary objective of this investigation is to analyze and compare the dynamic behavior of framed structures made of orthotropic materials manufactured by the pultrusion process. Pultruded flat beams made of glass/epoxy, graphite/epoxy and various lay-up combinations of hybrid glass-graphite/epoxy are used to produce high-modulus and lightweight, L-shaped, portal frame and other composite material structures. The dynamic properties of the decoupled and mechanically fastened coupled structures were obtained by the experimental modal analysis technique. The structural properties identification process for each of the beam and lumped systems consists of generating the frequency response functions (FRF), estimation of natural frequencies, damping, and the associated mode shapes. A measurement chain comprising a dual-channel dynamic signal analyzer, corresponding instruments and a modal analysis software package has been used for identifying the modal parameters. The experimental results demonstrate the applicability and dynamic superiority of structures made with pultruded hybrid composite materials.

Energy-saving and environment protecting integral vehicular rain test apparatus

Abstract: An energy-saving and environment-friendly entire car rain test device comprises a portal frame which is composed of steel pipes, spray heads installed on the portal frame, a shift device of the portal frame and a water circulation system, wherein, the shift device of the portal frame consists of a towing plate that is fixedly connected with the upper part of the portal frame, a motor fixed at the end part of the towing plate, an idler wheel fixed with an output shaft of the motor and a lead rail corresponding to the idler wheel that is installed on the lead rail. The entire car rain test device adopts the form that the portal frame evenly and slowly moves along the vertical direction of the vehicle, and utilizes spray heads or nozzles with the corresponding quantity installed on the portal frame to spray out the water flow with the intensity of pressure and water discharge achieving iron standard requirements, thereby ensuring all the parts of the vehicle to have consistent water reception time and leading the spraying effect of the entire car to achieve the iron standard requirements; after the entire car is sprayed, the waste water returns into a water storage trough, environmental pollution is not caused, thereby achieving the aim of environmental protection; the back flowed waste water is recycled after being precipitated and filtered, thereby saving the water resource.