Portal frame

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

Small -size triaxial engraver

Abstract: The utility model discloses a small -size triaxial engraver, including the base, locate workstation, portal frame on the base, locate aircraft nose on the portal frame, locate electric main shaft and control box on the aircraft nose, be equipped with control board, power supply, X axle step actuator, Y axle step actuator and Z axle step actuator in the control box, be equipped with USB interface module, bluetooth module and WIFI module on the control board, wherein, base, workstation, portal frame and control box all adopt the PVC board to make Adopt the utility model discloses can realize remote control, easy operation, it is nimble convenient, and compact structure, small in size, the low price, fail safe nature is high, but the wide application is in desktop teaching or processing production

Dynamic Soil-structure Interaction of Portal Frame Bridge Walls for High-speed Railways

Abstract: In Sweden, high-speed railways is a subject for public debate. The first stage of a high-speed train network, Ostlanken between Stockholm and Linkoping, is under investigation, and is planned to be trafficked in 2028. The high-speed railway is intended to hold traffic with speeds up to 320 km/h. At such speeds, the design requirements of the accelerations of the bridge superstructure become more stringent. Previous studies show that the interaction between the bridge and the backfill soil can reduce these accelerations. In this thesis, dynamic soil-structure interaction (SSI) of portal frame bridge walls has been studied. The SSI was represented by complex impedance functions that were calculated and analyzed for different parameters of a bridge-embankment interface. The impedance, representing dynamic stiffness and damping, were in this thesis calculated in the frequency domain with finite element (FE) software, by performing steady state analyses on 3D solid bridge-embankment models. To discretize the infinite extent of an embankment, the standard viscous boundary method was used, implemented by inserting infinite continuum elements at the boundary in the FE-software ABAQUS. The method showed successful with mitigating waves at the boundary. A parameter study was conducted, where the influence of geometries and material properties were shown through a comparison of impedance functions. Both embankments on a fixed boundary, representing bedrock, and embankments on circular ground soil plates of various thickness and stiffness, were compared. SSI showed to induce large amounts of dynamic stiffness and damping to a bridge structure. A stiffer embankment, as well as a stiffer ground soil, has shown large influence on the dynamic stiffness and is believed to reduce vibrations in a bridge deck. The study suggested that proper material modeling is important for both the soil and the concrete, to receive accuracy in the impedance functions. The work also indicates that a properly designed bridge wall geometry could be an important step towards developing the design of future high-speed railway bridges.

A comparative study of different measures to mitigate ground borne noise and vibration from underground trains

Abstract: This paper deals with vibration isolation of a building exposed to ground-borne vibrations induced by a moving train in a metro tunnel. The design of vibration isolation countermeasures, such as floating slab tracks or base isolation, is usually performed using simplified design rules based on SDOF models. These prediction methods can only give a rough estimate of the vibration reduction. On the other hand, complex three-dimensional coupled models are available that can predict ground-borne vibrations and noise in structures. Complex models can cover the whole vibration chain starting with vibration generation by a moving vehicle and ending with the re-radiated noise in the building’s rooms. The aim of the present paper is to compare the accuracy of simplified and complex models when assessing the effectiveness of vibration and noise isolation countermeasures. The performance of the countermeasures is demonstrated on the example of a three-story portal frame office building located above a straight metro tunnel. The response in the free field due to the passage of a vehicle on a uneven track is predicted in the frequency range 1-150 Hz and vibrations and re-radiated noise in the multi-story portal frame office building are subsequently estimated. The countermeasures considered are a floating slab track, base isolation of the structure and the application of a box-within-box arrangement. The performance of the countermeasures is evaluated using local and integrated insertion loss indicators and the results are compared with those obtained by simplified design models. The results show that the simple SDOF models overestimate the vibration isolation efficiency in the higher frequency range, while the complex numerical tool yields a more realistic estimate and a better understanding of vibration isolation.

Take frame green unilaterally to press lamination machine

Abstract: The utility model discloses a take frame green unilaterally to press lamination machine has solved the problem that current equipment can't satisfy the requirement of the production technology of the low -loss FERRO material of high frequency. Include and be provided with the fore -and -aft direction and remove frame cutting assembly portal frame (32) in that the top surface left end of lamination machine frame (31) is fixed, control the direction and remove the frame cutting assembly portal frame (33) and the portal frame stand of presenting a theatrical performance as the last item on a programme, removing frame cutting assembly portal frame (32), the fore -and -aft direction be provided with green piece front and back cutting assembly on, cutting assembly about being provided with on frame cutting assembly portal frame (33) is removed to left and right sides direction, be provided with on the portal frame stand of presenting a theatrical performance as the last item on a programme and present a theatrical performance as the last item on a programme, go up at lamination machine frame (31) and fix the mobile rail that presents a theatrical performance as the last item on a programme under and that presents a theatrical performance as the last item on a programme rail brackets (1) under being provided with, present a theatrical performance as the last item on a programme under and present a theatrical performance as the last item on a programme under being provided with on the mobile rail. The utility model discloses satisfied the requirement of the production technology of the low -loss FERRO material of high frequency, raw and other materials have been saved to the lamination high quality.

Telescopic leader cable bracket

Abstract: The utility model discloses a telescopic leader cable bracket. The telescopic leader cable bracket comprises portal frames, connecting supports, trundles, side bracing plates and bracing plate supports. Each portal frame is formed by connecting stand columns, supporting columns and portal beams. The trundles are arranged at the bottoms of the stand columns of the portal frames. The connecting supports are connected to the supporting columns of the portal frames in a cross and pin joint mode, and the multiple portal frames are connected together in series through the connecting supports to form a telescopic frame body. The side bracing plates and the bracing plate supports are installed outside the stand columns of the corresponding portal frames. The telescopic leader cable bracket can stretch or contract according to the length of a leader cable to be treated, thereby bringing great convenience to operation, reducing the labor intensity of workers and being high in working efficiency; the telescopic leader cable bracket can be folded when not in use, thereby greatly saving the space of a site. Furthermore, the cable can be integrally supported or transferred through the leader cable bracket.