Mechanistic research on the complex motion response of a TLP under tendon breakage

2021 ◽  
Vol 240 ◽  
pp. 109984
Author(s):  
Siyuan Cheng ◽  
Yang Yu ◽  
Jianxing Yu ◽  
Jingyi Wu ◽  
Zhenmian Li ◽  
...  
Author(s):  
Julie Mapes Lindholm ◽  
Paul A. Wetzel ◽  
Timothy M. Askins

2012 ◽  
Author(s):  
Joshua Haworth ◽  
Nathaniel Hunt ◽  
Yawen Yu ◽  
Nicholas Stergiou

2021 ◽  
Vol 9 (5) ◽  
pp. 543
Author(s):  
Jiawen Li ◽  
Jingyu Bian ◽  
Yuxiang Ma ◽  
Yichen Jiang

A typhoon is a restrictive factor in the development of floating wind power in China. However, the influences of multistage typhoon wind and waves on offshore wind turbines have not yet been studied. Based on Typhoon Mangkhut, in this study, the characteristics of the motion response and structural loads of an offshore wind turbine are investigated during the travel process. For this purpose, a framework is established and verified for investigating the typhoon-induced effects of offshore wind turbines, including a multistage typhoon wave field and a coupled dynamic model of offshore wind turbines. On this basis, the motion response and structural loads of different stages are calculated and analyzed systematically. The results show that the maximum response does not exactly correspond to the maximum wave or wind stage. Considering only the maximum wave height or wind speed may underestimate the motion response during the traveling process of the typhoon, which has problems in guiding the anti-typhoon design of offshore wind turbines. In addition, the coupling motion between the floating foundation and turbine should be considered in the safety evaluation of the floating offshore wind turbine under typhoon conditions.


Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Liuhao Zhu ◽  
Miaomiao Tang ◽  
Hehe Li ◽  
Yuping Tai ◽  
Xinzhong Li

Abstract Generally, an optical vortex lattice (OVL) is generated via the superposition of two specific vortex beams. Thus far, OVL has been successfully employed to trap atoms via the dark cores. The topological charge (TC) on each optical vortex (OV) in the lattice is only ±1. Consequently, the orbital angular momentum (OAM) on the lattice is ignored. To expand the potential applications, it is necessary to rediscover and exploit OAM. Here we propose a novel high-order OVL (HO-OVL) that combines the phase multiplication and the arbitrary mode-controllable techniques. TC on each OV in the lattice is up to 51, which generates sufficient OAM to manipulate microparticles. Thereafter, the entire lattice can be modulated to desirable arbitrary modes. Finally, yeast cells are trapped and rotated by the proposed HO-OVL. To the best of our knowledge, this is the first realization of the complex motion of microparticles via OVL. Thus, this work successfully exploits OAM on OVL, thereby revealing potential applications in particle manipulation and optical tweezers.


2011 ◽  
Vol 11 (13) ◽  
pp. 10-10 ◽  
Author(s):  
L. Kaunitz ◽  
A. Fracasso ◽  
D. Melcher
Keyword(s):  

Robotica ◽  
2001 ◽  
Vol 19 (1) ◽  
pp. 87-91 ◽  
Author(s):  
M. Guihard ◽  
P. Gorce

The aim of this paper is to propose a bipedal structure able to follow high acceleration movements. The vertical jump of a human has been chosen as input (coming from experiments) to validate the controller design as it is one of the most complex motion. The study concerns the low level of the biped control that is to say the control design of one leg made of three rigid bodies, each of them moved by a pneumatic actuator. An analogy between a pneumatic actuator and a physiological muscle is first proposed. A dynamic model of the leg is then presented decoupling the dynamic effects of the skeletal (as interactions between segments) from the dynamic effects of the muscles involved. The controller is based on the nonlinear theory (taking into account the actuator and the mechanical models), it ensures a dynamic tracking of position and force. Its originality lays in the consideration of impedance behaviour at each joint during free and constrained tasks. It leads to asymptotically stable (Popov criteria) control laws which are continuous between contact and non-contact phases enabling real-time computations. The simulation results clearly show the tracking of position and forces during the whole jump cycle.


2021 ◽  
Vol 234 ◽  
pp. 109275
Author(s):  
Islam Amin ◽  
Saishuai Dai ◽  
Sandy Day ◽  
Mohamed E.A. Ali ◽  
Ahmed Balah ◽  
...  

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