We wczesnych godzinach rannych w S24 pojawila się notka
http://cheshire-cat.salon24.pl/580594,poszukiwany-poszukiwana
Autor tej notki zwierzył się czytelnikom ze swoich marzeń:
Czytając wpisy dotyczące tematu wpadłem na pomysł (z pewnością malo oryginalny), żeby się skontaktować z autorami wiekopomnego dzieła"Application of Numerical Methods for Crashworthiness Investigation of a Large Aircraft Wing Impact with a Tree", autorstwa panów Chao Zhanga, Wieslawa K. Biniendy, Franka E. Horvata i Wenzhi Wanga, żeby dowiedzieć się czegoś bliższego na temat wymiarów użytych w modelu
Zwracanie się do prof. Biniendy uznałem za stratę czasu, więc postanowiłem poszukać pozostałych.
Autor przedstawił rezultaty swoich poszukiwań. Mimo licznych wysiłków nie udało mu się skontaktować z p. Chao Zhang,
W każdym razie zacząłem się przyglądać p. Zhangowi. Informacji o nim równiez co kot napłakał. Doktorat planował zrobić w grudniu 2013, ale cztery miesiące w pracy naukowej to pewnie niewielka obsuwa. Szuka też pracy. Ale wolno mu.
Wyraźnie zniechęcony rezultatami poszukiwań, autor notki napisał:
Zaczęło we mnie kiełkowac podejrzenie, że ekipa Biniendy to fikcja. Że jego współpracownicy nie istnieją, albo ukrywają się pod pseudonimami, zmuszeni do firmowania swoimi nazwiskami bajek Biniendy.
Ponieważ jesteśmy dwa dni po Wielkanocy, odezwało się we mnie chrześcijańskie miłosierdzie i wyrozumiałość dla ludzkiego kalectwa. Postanowiłam pomóc człowiekowi. Niech się funkcyjna bidula nie męczy.
Oto rezultaty mojej krótkiej kwerendy:
Na stroniehttp://www.ecgf.uakron.edu/~civil/people/binienda/zhang.html czytamy:
Chao Zhang
Graduate Assistant
Civil Engineering Department
The University of Akron
302 Buchtel Commons
Akron, OH 44325-3905
330-732-7845
cz14@zips.uakron.edu
I am now looking for an academy position!
Dalsze poszukiwania pozwaliły ustalić, że autor notki pisząc, że p. Chao Hang Doktorat planował zrobić w grudniu 2013, ale cztery miesiące w pracy naukowej to pewnie niewielka obsuwa, minąl się z prawdą.
Otóż pan Chao Zhang obronił swoją pracę doktorską już 7 listopada, czyli przed zaplanowanym terminem.Zatem „obsuwy” nie było.
A temat tej pracy:
"Multi-scale Characterization and Failure Modeling of Carbon/Epoxy Triaxially Braided Composite"
A to skład komisji (Committee members):
Dr. R. Goldberg, Dr. A. Patnaik, Dr. E. Pan, Dr. E. Sancaktar, and Dr. Xiaosheng Gao,
Data obrony: November 7, 2013.
Pan dr Chao Zhang jest młodym, dobrze się zapowiadającym naukowcem i mimo swego młodego wieku ma już pięć publikacji w poważnych czasopismach. Oto one:
Chao Zhang,Wieslaw K. Binienda,Robert K. Goldberg,Lee W. Kohlman,Meso-scale failure modeling of single layer triaxial braided composite using finite element method, Composites, Part A, Applied Science and Manufacturing 01/2014; 58:36–46. · 2.74 Impact Factor
Abstract:
In this study, a meso-scale finite element (FE) model of a triaxial braided composite is generated based on realistic unit cell dimensions and fiber bundle geometry parameters. Micromechanical finite element models were developed to predict the elastic and strength properties of each fiber bundle. These details are then applied in a 14 unit cells meso-mechanical finite element model for a 0°/+60°/−60° triaxially braided T700s/E862 carbon/epoxy composite. Simulations of the axial tension and transverse tension response of a straight-sided, single layer coupon are conducted using this mesoscale model, and the predictions are compared to experimental results. By applying a periodic boundary condition in the loading direction and an accurate number of unit cells perpendicular to the free edge, the mesoscale model captures the local damage initiation and global failure behavior, as well as the periodic free edge distortion effect. The failure mechanisms are studied using the field strain and stress contours.
Chao Zhang,Wieslaw K Binienda,Lee W Kohlman,Analytical and Numerical Analysis on Elastic Behavior of Triaxial Braided Composites,Journal of Aerospace Engineering. 01/2013;
Chao Zhang,Wieslaw K. Binienda,Liming Zeng,Xiaochuan Ye,Shuwen Chen,Kinetic study of the novolac resin curing process using model fitting and model-free methods, Thermochimica Acta - THERMOCHIM ACTA. 01/2011; 523(1):63-69.
Abstract:
The curing behavior of novolac type phenolic resin was studied through differential scanning calorimetry (DSC) using model fitting and model-free (isoconversion) kinetic methods. For the model fitting kinetic study, a piecewise fitting approach was developed to describe the dependence of cure reaction rate on temperature and curing degree. The piecewise model displayed excellent modeling ability. In the model-free kinetic study, Friedman, and Kissinger–Akahira–Sunose methods were used to calculate the curing activation energy. The dependence curve of activation energy on conversion and the piecewise model fitting results both displayed a change in the kinetic reaction mechanism from the autocatalytic to n-order regime. According to the isothermal prediction results, the model-free kinetic methods show much better prediction ability, compared with the model fitting methods. Also, Friedman and Kissinger–Akahira–Sunose methods were found to show similar results in predicting the isothermal curing behavior of this novolac resin.
Chao Zhang,Wieslaw K. Binienda,Gregory N. Morscher,Richard E. Martin,Lee W. Kohlman,Experimental and FEM study of thermal cycling induced microcracking in carbon/epoxy triaxial braided composites, Composites, Part A, Applied Science and Manufacturing 46:34–44. · 2.74 Impact Factor
Abstract:
The microcrack distribution and mass change in T700s/PR520 and T700s/3502 carbon/epoxy braided composites exposed to thermal cycling was evaluated experimentally. Acoustic emission was utilized to record the crack initiation and propagation under cyclic thermal loading between −55 °C and 120 °C. Transverse microcrack morphology was investigated using X-ray computed tomography. The differing performance of two kinds of composites was discovered and analyzed. Based on the observations of microcrack formation, a meso-mechanical finite element model was developed to obtain the resultant mechanical properties. The simulation results exhibited a decrease in strength and stiffness with increasing crack density. Strength and stiffness reduction versus crack densities in different orientations were compared. The changes of global mechanical behavior in both axial and transverse loading conditions were studied. By accounting for the obtained reduction of mechanical properties, a macro-mechanical finite element model was utilized to investigate the influence of microcracking on the high-speed impact behavior.
Chao Zhang1, Wieslaw K. Binienda1, Frank E. Horvat2, Wenzhi Wang3,Application of numerical methods for crashworthiness investigation on aircraft wing impact with tree, Mathematical and Computational Forestry&Natural-Resource Sciences. 03/2013; 5(1):71-85.
http://www.researchgate.net/profile/Chao_Zhang40/publications
1Department of Civil Engineering, University of Akron, 302 Buchtel Common, Akron, OH, 44325, USA
2Department of Mechanical Engineering, University of Akron, 302 Buchtel Common, Akron, OH, 44325, USA
3School of Aeronautics, Northwestern Polytechnical University, Xian, Shaanxi 710072, China
Abstract.
This paper demonstrates the application of a numerical methodology for a full-scale aircraft impact crashworthiness investigation. We studied the impact of an aircraft wing with a tree using LS-DYNA and ANSYS CFX. In particular, a detailed finite element model of the wing structure was represented as a box structure containing skin, spars and ribs, and fuel was represented as a distributed mass. We utilized several material models and verified them using leading-edge bird strike and wood bending experiments. Wood model Mat 143 with material parameters developed based on the wood bending test was found to be the most accurate in comparison with the experiment. We used the commercially available Computational Fluid Dynamics (CFD) software of ANSYS CFX to calculate the aerodynamic pressure distribution on the overall surface of the wing. The algorithm utilized the full three-dimensional Navier-Stokes equations for steady-state compressible fluid. LS-DYNA finite element model included aerodynamic pressures on the wings surfaces.Parametric studies showed that the tree model cannot destroy the lifting surface of the wing except the fragment of the leading edge. In every simulation scenario, the first spar of the wing cut through the tree and the upper part of the tree fell in the direction of the movement of the airplane.
Keywords:
Mat 143, Johnson-Cook material model, fluid dynamics, aircraft, wing, tree. Full scale modeling, Finite Element Method, crashworthiness, nonlinear wood model,
Ostatnia z tych publikacji jest szczególnie istotna dla autora omawianej notki, poszukującego kontaktu ze współpracownikami prof. Wiesława Biniendy. Wielka szkoda, że „poszukiwacz” nie zadal sobie trudu aby chociaż zerknąć na streszczenie tej publikacji. Dowiedziałby się bowiem, gdzie pracują owi współpracownicy prof. Biniendy i wtedy, być może, nie zawracałby doopy czytelnikom.
Oto te informacje (będzie dużymi drukowanymi literami, aby dotarło do prostych umysłów):
Frank E. Horvat-Department of Mechanical Engineering, University of Akron, 302 Buchtel Common, Akron, OH, 44325, USA
Wenzhi Wang-School of Aeronautics, Northwestern Polytechnical University, Xian, Shaanxi 710072, China
