Aeroelastic Responses for Wind Turbine Blade Considering Bend-Twist Coupled Effect

The Euler-Bernoulli beam model coupled with the sectional properties obtained by the variational asymptotic beam sectional analysis(VABS)method is used to construct the blade structure model.Combined the aerodynamic loads calculated by unsteady blade element momentum model with a dynamic inflow and the dynamic stall correction,the dynamics equations of blade are built.The Newmark implicit algorithm is used to solve the dynamics equations.Results of the sectional properties and blade structure model are compared with the multi-cell beam method and the ANSYS using shell elements.It is proved that the method is effective with high precision.Moreover,the effects on the aeroelastic response caused by bend-twist coupling are analyzed.Torsional direction is deflected toward the upwind direction as a result of coupling effects.The aerodynamic loads and the displacement are reduced.

SECTIONAL FINITE ELEMENT ANALYSIS OF COUPLED DEFORMATION BETWEEN ELASTOPLASTIC SHEET METAL AND VISCO-ELASTOPLASTIC BODY

The present paper is devoted to developing a new numerical simulation method for the analysis of viscous pressure forming （VPF）, which is a sheet flexible-die forming （FDF） process. The pressure-carrying medium used in VPF is one kind of semisolid, flowable and viscous material and its deformation behavior can be described by the visco-elastoplastic constitutive model. A sectional finite element model for the coupled deformation analysis between the viscoelastoplastic pressure-carrying medium and the elastoplastic sheet metal is proposed. The resolution of the Updated Lagrangian （UL） formulation is based on a static explicit approach. The frictional contact between sheet metal and visco-elastoplastic pressure-carrying medium is treated by the penalty function method. Coupled deformation between sheet metal and visco-elastoplastic pressure-carrying medium with large slip is analyzed to validate the developed algorithm. Finally, the viscous pressure bulging （VPB） process of DC06 sheet metal is simulated. Good agreement between numerical simulation results and experimental measurements shows the validity of the developed algorithm.

Histological examination of frozen sections for patients with acute cholecystitis during cholecystectomy

BACKGROUND： Unexpected gallbladder cancer may present with acute cholecystitis-like manifestat/ons. Some authors rec- ommended that frozen section analysis should be performed during laparoscopic cholecystectomy for all cases of acute cholecystitis. Others advocate selective use of frozen section analysis based on gross examination of the specimen by the surgeon. The aim of the present study was to evaluate whether surgeons could effectively identify suspected gallbladder with macroscopic examination alone. If not, is routine frozen sec- tion analysis worth advocating？

Skeleton-Sectional Structural Analysis for 3D Printing

3D printing has become popular and has been widely used in various applications in recent years. More and more home users have motivation to design their own models and then fabricate them using 3D printers. However, the printed objects may have some structural or stress defects as the users may be lack of knowledge on stress analysis on 3D models. In this paper, we present an approach to help users analyze a model＇s structural strength while designing its shape. We adopt sectional structural analysis instead of conventional FEM （Finite Element Method） analysis which is computationally expensive. Based on sectional structural analysis, our approach imports skeletons to assist in integrating mesh designing, strength computing and mesh correction well. Skeletons can also guide sections building and load calculation for analysis. For weak regions with high stress over a threshold value in the model from analysis result, our system corrects them by scaling the corresponding bones of skeleton so as to make these regions stiff enough. A number of experiments have demonstrated the applicability and practicability of our approach.