Topic
Portal frame
About: Portal frame is a research topic. Over the lifetime, 1778 publications have been published within this topic receiving 7210 citations.
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06 Dec 2006
TL;DR: In this paper, a portal tower structure is used to construct an automatic assembling machine for digital-controlled H-type steels, where a downward pressing oil cylinder is connected with a movable cross beam, and the movable beam is provided with an automatic tracking frame with welded elevation angles.
Abstract: The utility model relates to an automatic assembling machine for digital-controlled H-type steels. The front part is a portal tower structure, and the upper part of a machine frame is provided with a downward pressing oil cylinder; the downward pressing oil cylinder is connected with a movable cross beam, and the movable cross beam is provided with an automatic tracking frame with welded elevation angles; a positioning box for underbelly wing plates and the clamping box are arranged at a portal base, and an input rolling channel is arranged under the portal frame; machine frames at both ends of the rolling channel are provided with automatic centering and clamping shafts for web plates, and a conveying motor is connected with a driving roller; a conveying chain wheel on the driving roller is connected with a roller on the input rolling channel by a chain, and welding seams have automatic tracking; two pneumatic tracking welding guns used for welding upper flanges are fixed on the cross beam and can carry out variation along with the variation of the height of H-type steel web plates, therefore H-type steels with variable cross sections can be welded; two pneumatic tracking welding guns used for welding lower flanges are fixed on an upright post, the welding guns are firmly fixed and the quality of welding seams is stable and reliable.
12 citations
01 Jan 1996
12 citations
TL;DR: This work presents a passive control strategy using a pendulum on a simple portal frame structure, with two-to-one internal resonance, with a piezoelectric material coupling as a means of energy harvesting, and shows that the system presents, most of the time, as being quasiperiodic.
Abstract: This work presents a passive control strategy using a pendulum on a simple portal frame structure, with two-to-one internal resonance, with a piezoelectric material coupling as a means of energy ha...
12 citations
TL;DR: In this article, an optimal design procedure for sandwich structures subject to frequency and section constraints is developed from direct comparison theorems for different designs, derived from the Rayleigh quotient for the structure.
Abstract: An optimal design procedure for sandwich structures subject to frequency and section constraints is developed from direct comparison theorems for different designs. These theorems are derived from the Rayleigh quotient for the structure. Applications to the axial motion of a bar and to the vibration of a portal frame are given.
12 citations