Dokument-ID Dokumenttyp Verfasser/Autoren Herausgeber Haupttitel Abstract Auflage Verlagsort Verlag Erscheinungsjahr Seitenzahl Schriftenreihe Titel Schriftenreihe Bandzahl ISBN Quelle der Hochschulschrift Konferenzname Bemerkung Quelle:Titel Quelle:Jahrgang Quelle:Heftnummer Quelle:Erste Seite Quelle:Letzte Seite URN DOI Zugriffsart Link Abteilungen OPUS4-3994 Wissenschaftlicher Artikel Pham, Phu Tinh, ; Vu, Khoi Duc, ; Tran, Thanh Ngoc, tran@fh-aachen.de; Staat, Manfred, m.staat@fh-aachen.de A primal-dual algorithm for shakedown analysis of elastic-plastic bounded linearly kinematic hardening bodies 2010 6 ECCM 2010, IV European Conference on Computational Mechanics, Paris, France, May 16-21, 2010. 1 7 weltweit http://www.eccm2010.org/complet/fullpaper_901.pdf Fachbereich Medizintechnik und Technomathematik OPUS4-4977 Konferenzveröffentlichung Tran, Thanh Ngoc, tran@fh-aachen.de; Staat, Manfred, m.staat@fh-aachen.de Eberhardsteiner, J. A primal-dual shakedown analysis of 3D structures using the face-based smoothed finite element method 2012 Proceedings European Congress on Computational Methods in Applied Sciences and Engineering (ECCOMAS 2012) 6th European Congress on Computational Methods in Applied Sciences and Engineering (ECCOMAS 2012) Vienna, Austria, September 10-14, 2012 Fachbereich Medizintechnik und Technomathematik OPUS4-4944 Wissenschaftlicher Artikel Tran, Thanh Ngoc, tran@fh-aachen.de; Staat, Manfred, m.staat@fh-aachen.de An Edge-Based Smoothed Finite Element Method for Primal-Dual Shakedown Analysis of Structures Under Uncertainties Dordrecht Springer 2013 VIII, 228 S., Ill., graph. Darst. Limit State of Materials and Structures : Direct Methods 2. Saxcé, Géry de (Hrsg.) 978-94-007-5424-9 89 102 bezahl http://dx.doi.org/10.1007/978-94-007-5425-6_5 Fachbereich Medizintechnik und Technomathematik OPUS4-191 Konferenzveröffentlichung Tran, Thanh Ngoc, tran@fh-aachen.de; Staat, Manfred, m.staat@fh-aachen.de; Kreißig, R., Calculation of load carrying capacity of shell structures with elasto-plastic material by direct methods Proceedings of the International Conference on Material Theory and Nonlinear Dynamics. MatDyn. Hanoi, Vietnam, Sept. 24-26, 2007, 8 p. In this paper, a method is introduced to determine the limit load of general shells using the finite element method. The method is based on an upper bound limit and shakedown analysis with elastic-perfectly plastic material model. A non-linear constrained optimisation problem is solved by using Newton's method in conjunction with a penalty method and the Lagrangean dual method. Numerical investigation of a pipe bend subjected to bending moments proves the effectiveness of the algorithm. 2007 Fachbereich Medizintechnik und Technomathematik OPUS4-9533 Wissenschaftlicher Artikel Nguyen-Xuan, H., ; Rabczuk, T., ; Nguyen-Thoi, T., ; Tran, Thanh Ngoc, tran@fh-aachen.de; Nguyen-Thanh, N., Computation of limit and shakedown loads using a node-based smoothed finite element method Weinheim Wiley 2011 23 International Journal for Numerical Methods in Engineering 90 3 287 310 10.1002/nme.3317 campus https://doi.org/10.1002/nme.3317 Fachbereich Medizintechnik und Technomathematik OPUS4-300 Konferenzveröffentlichung Tran, Thanh Ngoc, tran@fh-aachen.de; Novacek, V., ; Tolba, R., ; Klinge, U., ; Turquier, F., ; Staat, Manfred, m.staat@fh-aachen.de Experimental and Computational approach to study colorectal anastomosis. ISB2011, Proceedings of the XXIII Congress of the International Society of Biomechanics, Brussels, Belgium, July 3-7, 2011 Summary: This paper presents a methodology to study and understand the mechanics of stapled anastomotic behaviors by combining empirical experimentation and finite element analysis. Performance of stapled anastomosis is studied in terms of leakage and numerical results which are compared to in vitro experiments performed on fresh porcine tissue. Results suggest that leaks occur between the tissue and staple legs penetrating through the tissue. 2011 Fachbereich Medizintechnik und Technomathematik OPUS4-7860 Konferenzveröffentlichung Tran, Ngoc Trinh, ; Tran, Thanh Ngoc, tran@fh-aachen.de; Matthies, Hermann G., ; Stavroulakis, Georgios Eleftherios, ; Staat, Manfred, m.staat@fh-aachen.de FEM Shakedown of uncertain structures by chance constrained programming 2016 1 PAMM Proceedings in Applied Mathematics and Mechanics 16 Special Issue: Joint 87th Annual Meeting of the International Association of Applied Mathematics and Mechanics (GAMM) and Deutsche Mathematiker-Vereinigung 1 715 716 10.1002/pamm.201610346 campus http://doi.org/10.1002/pamm.201610346 Fachbereich Medizintechnik und Technomathematik OPUS4-4811 Wissenschaftlicher Artikel Novacek, V., ; Tran, Thanh Ngoc, tran@fh-aachen.de; Klinge, U., ; Tolba, R. H., ; Staat, Manfred, m.staat@fh-aachen.de; Bronson, D. G., ; Miesse, A. M., ; Whiffen, J., ; Turquier, F., Finite element modelling of stapled colorectal end-to-end anastomosis : Advantages of variable height stapler design The impact of surgical staplers on tissues has been studied mostly in an empirical manner. In this paper, finite element method was used to clarify the mechanics of tissue stapling and associated phenomena. Various stapling modalities and several designs of circular staplers were investigated to evaluate the impact of the device on tissues and mechanical performance of the end-to-end colorectal anastomosis. Numerical simulations demonstrated that a single row of staples is not adequate to resist leakage due to non-linear buckling and opening of the tissue layers between two adjacent staples. Compared to the single staple row configuration, significant increase in stress experienced by the tissue at the inner staple rows was observed in two and three rows designs. On the other hand, adding second and/or third staple row had no effect on strain in the tissue inside the staples. Variable height design with higher staples in outer rows significantly reduced the stresses and strains in outer rows when compared to the same configuration with flat cartridge. Amsterdam Elsevier 2012 4 Journal of Biomechanics 45 115 2693 2697 10.1016/j.jbiomech.2012.07.021 campus https://doi.org/10.1016/j.jbiomech.2012.07.021 Fachbereich Medizintechnik und Technomathematik OPUS4-196 Konferenzveröffentlichung Tran, Thanh Ngoc, tran@fh-aachen.de; Staat, Manfred, m.staat@fh-aachen.de; Kreißig, R., Finite element shakedown and limit reliability analysis of thin shells A procedure for the evaluation of the failure probability of elastic-plastic thin shell structures is presented. The procedure involves a deterministic limit and shakedown analysis for each probabilistic iteration which is based on the kinematical approach and the use the exact Ilyushin yield surface. Based on a direct definition of the limit state function, the non-linear problems may be efficiently solved by using the First and Second Order Reliabiblity Methods (Form/SORM). This direct approach reduces considerably the necessary knowledge of uncertain technological input data, computing costs and the numerical error. In: Computational plasticity / ed. by Eugenio Onate. Dordrecht: Springer 2007. VII, 265 S. (Computational Methods in Applied Sciences ; 7) (COMPLAS IX. Part 1 . International Center for Numerical Methods in Engineering (CIMNE)). ISBN 978-1-402-06576-7 S. 186-189 2007 Fachbereich Medizintechnik und Technomathematik OPUS4-4812 Wissenschaftlicher Artikel Nguyen, Nhu Huynh, ; Duong, Minh Tuan, duong@fh-aachen.de; Tran, Thanh Ngoc, tran@fh-aachen.de; Pham, Phu Tinh, ; Grottke, O., ; Tolba, R., ; Staat, Manfred, m.staat@fh-aachen.de Influence of a freeze-thaw cycle on the stress-stretch curves of tissues of porcine abdominal organs The paper investigates both fresh porcine spleen and liver and the possible decomposition of these organs under a freeze-thaw cycle. The effect of tissue preservation condition is an important factor which should be taken into account for protracted biomechanical tests. In this work, tension tests were conducted for a large number of tissue specimens from twenty pigs divided into two groups of 10. Concretely, the first group was tested in fresh state; the other one was tested after a freeze-thaw cycle which simulates the conservation conditions before biomechanical experiments. A modified Fung model for isotropic behavior was adopted for the curve fitting of each kind of tissues. Experimental results show strong effects of the realistic freeze-thaw cycle on the capsule of elastin-rich spleen but negligible effects on the liver which virtually contains no elastin. This different behavior could be explained by the autolysis of elastin by elastolytic enzymes during the warmer period after thawing. Realistic biomechanical properties of elastin-rich organs can only be expected if really fresh tissue is tested. The observations are supported by tests of intestines. Amsterdam Elsevier 2012 4 Journal of Biomechanics 45 14 2382 2386 10.1016/j.jbiomech.2012.07.008 campus https://doi.org/10.1016/j.jbiomech.2012.07.008 Fachbereich Medizintechnik und Technomathematik