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Journal of shanghai jiaotong university(Science) 2010年第3期15卷 340-345页

作者：石珣陈新权谭家华 school of naval architecture Ocean and Civil EngineeringShanghai Jiaotong University

Owing to the special working characteristics and operation requirements,lots of working ships have notches in different sizes and shapes in their *** order to study the resistance performance of the vessel with notches,a series of model resistance tests were performed in respect to the 4 500 m 3 /h cutter suction dredger,and the tests were simulated based on the computational fluid dynamics software *** on analysis to the experimental data and the computational fluid dynamics(CFD) calculation results,the change of the flow field and the resistance performance caused by the notches were studied,and the reliability of the software in simulation of viscous flow around the hull was *** provides the basis for the future study and the design optimization of this kind of working ships.

关键词： ship resistance ship model test computational fluid dynamics(CFD) notch cutter suction dredger

Experimental Study on Mechanical Behavior of Box-Brace to Box-Column Foot Joints

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Journal of shanghai jiaotong university(Science) 2012年第4期17卷 385-390页

作者：王兆强赵金城龚景海 school of naval architecture Ocean and Civil EngineeringShanghai Jiaotong University

This paper presents results of three tests carried out to study the mechanical behavior of foot joints used in the tower boiler steel frame. Each foot joint consists of a box column and a box brace. These three specimens have different connection types or different details of stiffeners. The tests are carried out by using the large multi-function structural experiment system WAW-1000J. The load-displacement curves and the strain distribution are measured during the tests. The mechanical behavior of foot joints under adverse load cases is analyzed. The safety of these three specimens under design load is assessed. The strength and deformation of different joints are compared. The results indicate that connection types or details of inner stiffeners have effects on strength and failure mode and that the specimen with end-plate connection can optimize the strain distribution along the height of brace web and can change the force transfer mechanism between column and brace. In addition, a finite element model of the specimen is conducted and numerical results generally agree well with the test results. The work in this paper provides a base for further analysis on the performance of joint used in the tower boiler steel frames.

关键词： foot joint tower boiler strength connection stiffener

Acoustic Radiation Analysis Based on Essential Solution of Green's Function

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Journal of shanghai jiaotong university(Science) 2013年第4期18卷 409-417页

作者：陈炉云张裕芳 school of naval architecture Ocean and Civil EngineeringShanghai Jiaotong University

The principle objective of the paper is to study the acoustic radiation problem of the 3D space domain with control boundary. By using the conformal transformation theory, the Green's function for acoustic point source in the control domain space is obtained. With it, the expression of acoustic radiation function of the control domain is formed. Discussion about the acoustic radiation of pulsating sphere in right-angle space is drawn in the end, including the acoustic radiation directivity effect by the boundary characteristics, acoustic radiation frequency and acoustic source location. Numerical results show that: for the lower frequency radiation, the infection of free surface is significant; for the high frequency radiation, the infection of location is significant on the contrary. The research provides a new method for boundary characteristic problem of the structural-acoustic acoustic.

关键词： Green's function conformal transformation method acoustic radiation directivity image point

Axi-symmetric Active Earth Pressure for Layered Backfills Obtained by the Slip Line Method

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Journal of shanghai jiaotong university(Science) 2008年第5期13卷 579-584页

作者：刘发前王建华张璐璐 school of naval architecture Ocean and Civil Engineering Shanghai Jiaotong University

The axi-symmetric active earth pressure for layered backfills was investigated using the slip line method. Due to different soil properties, the interfaces of the soil layers were considered as discontinuity surface. Accordingly, the change of the major principal direction was obtained and a new computation scheme was proposed to deal with the discontinuity in the calculation, finally the slip line method was extended to layered backfills. Results indicate that, the major principal direction, as well as the earth pressure, has a finite jump on passing the soil interfaces. The magnitude of the jump depends on the soil properties mainly. Generally, the active earth pressure when a strong layer is overlying a weak layer is much larger than that when the weak layer is lying on the strong layer. The present solution can be reduced to plane strain case and it has been compared with Rankine's and Coulomb's results, and a good agreement is observed.

关键词： axi-symmetry earth pressure slip line method layered backfill soil-wall friction

Alterable-element Method for Vehicle-bridge Interaction Considering the Transient Jump of Wheel

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Journal of shanghai jiaotong university(Science) 2008年第3期13卷 330-335页

作者：吴川刘学文黄醒春 school of naval architecture Ocean and Civil Engineering Shanghai Jiaotong University

The so called "alterable-element method" (AEM) was introduced to deal with the coupling interac-tion of vehicle and sub-structure considering the actual transient jump of wheel, while the classical "contact all along" assumption based on which wheels and lower structure are always contact was abandoned. The alterable element used in this method is a conceptional element, which is used to calculate the coupling interaction of upper and lower structures and has some typical characteristics: firstly it flows along with the moving of contact point; secondly whether it is used for calculation depends on the contact state; thirdly its sizes could change according to specific problems and so on. VISUAL FORTRAN program was coded, and different moving vehicle models were presented taking into consideration the effects of random corrugation in the numerical study. The numerical solutions are favored comparing with the results obtained by alternative methods when there is no jump phenomenon existed. With abrupt irregularity, the transient jump of wheel was studied using the present method.

关键词： alterable-element method (AEM) vehicle-bridge interaction transient jump

Dynamic Investigation on Composite Flexible Multi-body System Considering Thermal Effect

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Journal of shanghai jiaotong university(Science) 2010年第4期15卷 414-422页

作者：潘科琪刘锦阳 school of naval architecture Ocean and Civil EngineeringShanghai Jiaotong University

The dynamic performance of composite flexible multi-body system under the simultaneous action of thermal fields and driving constraint is analyzed. Based on strain-displacement relation of the Mindlin plate theory which includes transverse shear deformation, and considering thermal effect, variation equations of laminated plate are derived by the principle of virtual work. The finite element method is used for discretization. According to kinematics constraint relation, dynamic equations for spatial slider-crank system are established. Simulation results show that spatial deformation （torsion deformation） appears in the multi-layered composite slider-crank mechanism which is simulated with planar motions. Furthermore, the influence of coupling between thermal expansion and flexible deformations of non-symmetrical composite plates on the large overall motion under the uniform temperature field is investigated. Finally, significant change in constraint force due to the spatial deformation is shown.

关键词： flexible multi-body system composite plate thermal effect spatial deformation

Prediction of Flexural Deformation of Reinforcement Concrete Beams with Polynomial Tension Stiffening Model

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Journal of Donghua university(English Edition) 2013年第2期30卷 83-89页

作者：杨淑雁刘西拉冷予冰 school of naval architecture Ocean and Civil EngineeringShanghai Jiaotong University

Based on an assumption of parabolic bond stress distribution,a simplified model with quartic polynomial function of the relative slip of steel bar and surrounding concrete for reinforced concrete (RC)tensile member was proposed. The post-cracking behavior as well as tension stiffening effect was considered in the new model. The relative slip of bending member could also be determined through the extension of the new model,which could be applied to obtaining the concentrated rotations at certain sections in order to predict the flexural deformation of RC beam. Several examples of four-point bending RC beams were approached to verify the new model,and the predictions of the flexural deflections of RC beams agreed well with experimental results. The new model can be extended to the application of partially corroded RC beam.

关键词： tension stiffening polynomial function reinforced concrete(RC) beam flexural deformation

A Low-Cost Testbed of Underwater Mobile Sensing Network

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Journal of shanghai jiaotong university(Science) 2011年第4期16卷 502-507页

作者：尚桂杨冯正平连琏 school of naval architecture Ocean and Civil EngineeringShanghai Jiaotong University

Comprised by a swarm of acoustically linked and cooperative autonomous underwater vehicles(AUVs) with onboard sensors,an underwater mobile sensing network(UMSN) will be a complementary means to fixed observatory networks,*** observatory networks and moored buoy *** has obvious advantages over a single large AUV in higher efficiency due to parallel observation,stronger robustness to vehicle failures and lower *** an UMSN can be viewed as a counterpart of wireless mobile sensing networks for air and terrestrial applications,it is much more challenging due to poor performance of underwater acoustic communication, poor performance of underwater positioning and high degree of uncertainty in vehicle dynamics and underwater *** order to verify key technologies involved in an UMSN,*** of multi-AUVs based on acoustic communication,a low cost testbed has been developed for experimental *** design of both hardware and software is *** the results of a functional test for verification of the effectiveness of the testbed are presented.

关键词： underwater mobile sensing network(UMSN) autonomous underwater vehicle(AUV) testbed coordination and cooperation control

Central Pattern Generator Based Gait Control for Planar Quadruped Robots

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Journal of shanghai jiaotong university(Science) 2014年第1期19卷 1-10页

作者：李家旺吴超葛彤 school of naval architecture Ocean and Civil Engineering Shanghai Jiaotong University

In this paper, a gait control scheme is presented for planar quadruped robots based on a biologic concept, namely central pattern generator(CPG). A CPG is modeled as a group of the coupled nonlinear oscillators with an interaction weighting matrix which determines the gait patterns. The CPG model, mapping functions and a proportional-diffierential(PD) joint controller compose the basic gait generator. By using the duty factor of gait patterns as a tonic signal, the activity of the CPG model can be modulated, and as a result, a smooth transition between diffierent gait patterns is achieved. Moreover, by tuning the parameters of the CPG model and mapping functions, the proposed basic gait generator can realize adaptive workspace trajectories for the robot to suit diffierent terrains. Simulation results illustrate and validate the effiectiveness of the proposed gait controllers.

关键词： quadruped robot central pattern generator(CPG) gait transition adaptation

Simulation Platform for the Underwater Snake-Like Robot Swimming Based on Kane's Dynamic Model and Central Pattern Generator

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Journal of shanghai jiaotong university(Science) 2014年第3期19卷 294-301页

作者：杨柯王旭阳葛彤吴超 school of naval architecture Ocean and Civil Engineering Shanghai Jiaotong University

A systematic method for swimming control of the underwater snake-like robot is still lacking. We construct a simulation platform of the underwater snake-like robot swimming based on Kane's dynamic model and central pattern generator(CPG). The partial velocity is deduced. The forces which contribute to dynamics are determined by Kane's approach. Hydrodynamic coefficients are determined by experiments. Then, we design a CPG-based control architecture implemented as the system of coupled nonlinear oscillators. The CPG, like its biological counterpart, can produce coordinated patterns of rhythmic activity while being modulated by simple control parameters. The relations between the CPG parameters and the speed of the underwater snake-like robot swimming are investigated. Swimming in a straight line, turning, and switching between swimming modes are implemented in our simulation platform to prove the feasibility of the proposed simulation platform. The results show that the simulation platform can imitate different swimming modes of the underwater snake-like robot.

关键词： underwater snake-like robot Kane’s dynamic model swimming central pattern generator(CPG)