Qingbin Li - Academia.edu (original) (raw)

Papers by Qingbin Li

Scientia Sinica Technologica, 2015

Journal of Aerospace Engineering, 2016

Mathematical Problems in Engineering, 2015

ABSTRACT This paper presents a new robust and efficient time integration algorithm suitable for v... more ABSTRACT This paper presents a new robust and efficient time integration algorithm suitable for various complex nonlinear structural dynamic finite element problems. Based on the idea of composition, the three-point backward difference formula and a generalized central difference formula are combined to constitute the implicit algorithm. Theoretical analysis indicates that the composite algorithm is a single-solver algorithm with satisfactory accuracy, unconditional stability, and second-order convergence rate. Moreover, without any additional parameters, the composite algorithm maintains a symmetric effective stiffness matrix and the computational cost is the same as that of the trapezoidal rule. And more merits of the proposed algorithm are revealed through several representative finite element examples by comparing with analytical solutions or solutions provided by other numerical techniques. Results show that not only the linear stiff problem but also the nonlinear problems involving nonlinearities of geometry, contact, and material can be solved efficiently and successfully by this composite algorithm. Thus the prospect of its implementation in existing finite element codes can be foreseen.

Magazine of Concrete Research, 2015

Advanced Materials Research, 2011

ABSTRACT

Shape Memory Alloys - Processing, Characterization and Applications, 2013

Mathematical Problems in Engineering, 2014

International Journal of Industrial Ergonomics, 1987

International Journal of Solids and Structures, 2001

Rock Mechanics and Rock Engineering, 2015

International Journal of Solids and Structures, 2004

International Journal of Modern Physics B, 2005

ABSTRACT The work presented in this paper bears on the feasibility and the operative technology o... more ABSTRACT The work presented in this paper bears on the feasibility and the operative technology of embedding electro-rheological (ER) fluids into cement mortar. We have made a cantilever mortar beam with controllable ER fluids filled in a central crack for the purpose of investigation on the evolutional rule of frequencies under different electric field strength by hammering test. The experimental results indicated that the influence of electric field strength upon the first frequency is more evident than that upon the second one, whereas that upon the third frequency is very little. In addition, the physical mechanism of the impact of the change of voltage on the frequency of smart beam structures embedded with ER fluids was discussed. This research sets up an experimental basis for the application of ER fluids in the domain of structural vibration control.

International Journal of Solids and Structures, 2002

Journal of Metallurgy, 2011

Sensing Issues in Civil Structural Health Monitoring, 2005

ABSTRACT Smart concrete beams with dimensions 1996cm × 99cm × 85cm were manufactured, six bounds ... more ABSTRACT Smart concrete beams with dimensions 1996cm × 99cm × 85cm were manufactured, six bounds of Shape Memory Alloy (SMA) were mounted in each beam as actuators. Experiment of the smart concrete beam was carried out, the temperature and the smart pre-stress of the SMA bundle, as the distortion of the beam, were monitored during the experiment. The results show that the smart concrete beam may change its performance as needed.

Arabian Journal of Geosciences, 2015

ABSTRACT Effects of the first filling process of the Xiluodu super-high arch dam are studied by b... more ABSTRACT Effects of the first filling process of the Xiluodu super-high arch dam are studied by both field monitoring and numerical modelling methods. The numerical modelling is conducted by the three-dimensional nonlinear finite element method, which takes into account the nonlinear contact of the transverse joints between dam monoliths and adopts both the design and feedback parameters of the dam. The results obtained from the various numerical analysis cases for different impounded water levels are comprehensively compared with those obtained from the field monitoring. Throughout this study, it is concluded that: (1) changes of the hydrostatic load resulting from the filling process have a significant effect on the deformation and stress states of the dam and foundation. The foundation settles as a consequence of consolidation of the reservoir bed under the effect of the water mass. During the filling process, the compressive stress of the dam in the sealed region increases in the arch direction while that in the cantilever direction decreases, which reveals an enhancement of dam thrust into the two banks. (2) The transverse joints between the dam monoliths are compressed almost over the entire height of the poured dam, and their aperture gradually decreases as the impounded water level increases. (3) The overall deformation of the Xiluodu dam is obviously affected by the uneven foundation settlement due to the complex reservoir basin. The tensile stress concentration appears at the crossing zone of the top of the dam’s sealed region and the dam-foundation interface. Thus, reasonable layout of steel bars and suitable jointing design are essential in these tensile stress concentration regions. (4) The dam behaviour predicted using the three-dimensional numerical modelling is in good agreements with that from the field measuring in terms of the stress and strain distribution characteristics in the dam and foundation, especially when the feedback parameters are adopted for the numerical analysis. The results from both the field monitoring and numerical modelling reveal that overall stability of the dam during the first filling process meets the dam operational requirements.

$Research paper thumbnail of An explanation for rate effect of concrete strength based on fracture toughness including free water viscosity$

Qinghua Daxue Xuebao/Journal of Tsinghua University

A robust H ∞ controller with state feedback was developed for vibration control of building struc... more A robust H ∞ controller with state feedback was developed for vibration control of building structure during seismic excitation or wind loads. The building structure can have uncertain system parameters and disturbances. The linear matrix inequalities were solved based on robust H ∞ control theory to optimize the number of actuators and their locations based on a minimum norm criterion. The integrated design of the robust controller and the actuator placement includes the interactions between the controller and the actuators. The validity and robustness of the method are confirmed through a simulation of a multilayer shear frame building structure.

International Journal of Distributed Sensor Networks

This paper studies the feasibility of a real-time monitoring system to provide prompt analysis su... more This paper studies the feasibility of a real-time monitoring system to provide prompt analysis support of workers’ behaviour on dam construction sites. The system makes use of wireless sensor tracking technology and a set of servers for the running of software, handling collected data, real-time site state visualization, and remote interaction communications. The low-level ZigBee-based tracking technology network hardware utilizing fingerprinting software technology was employed. The system was found to be able to cover a large field whilst retaining its simple and easily deployable features. The proposed system was successfully implemented on the Xiluodu arch dam construction site and ultimately helped overcome the original shortcomings in worker safety management and has advanced the means of administration and management’s awareness and culture to new levels. The field tests also show that the received signal strength indicator (RSSI)-based localization algorithm implemented on Z...

Finite Elements in Analysis and Design, 2015