TY  - CHAP
A1  - Bhattarai, Aroj
A1  - Frotscher, Ralf
A1  - Staat, Manfred
T1  - Computational Analysis of Pelvic Floor Dysfunction
T2  - Women's Health and Biomechanics
N2  - Pelvic floor dysfunction (PFD) is characterized by the failure of the levator ani (LA) muscle to maintain the pelvic hiatus, resulting in the descent of the pelvic organs below the pubococcygeal line. This chapter adopts the modified Humphrey material model to consider the effect of the muscle fiber on passive stretching of the LA muscle. The deformation of the LA muscle subjected to intra-abdominal pressure during Valsalva maneuver is compared with the magnetic resonance imaging (MRI) examination of a nulliparous female. Numerical result shows that the fiber-based Humphrey model simulates the muscle behavior better than isotropic constitutive models. Greater posterior movement of the LA muscle widens the levator hiatus due to lack of support from the anococcygeal ligament and the perineal structure as a consequence of birth-related injury and aging. Old and multiparous females with uncontrolled urogenital and rectal hiatus tend to develop PFDs such as prolapse and incontinence.
KW  - Pelvic muscle
KW  - Muscle fibers
KW  - Passive stretching
KW  - Pelvic floor dysfunction
Y1  - 2018
SN  - 978-3-319-71574-2
U6  - https://doi.org/10.1007/978-3-319-71574-2_17
N1  - Lecture Notes in Computational Vision and Biomechanics, vol 29
SP  - 217
EP  - 230
PB  - Springer
CY  - Cham
ER  - 
TY  - CHAP
A1  - Tran, N. T.
A1  - Tran, Thanh Ngoc
A1  - Matthies, M. G.
A1  - Stavroulakis, G. E.
A1  - Staat, Manfred
T1  - Shakedown Analysis Under Stochastic Uncertainty by Chance Constrained Programming
T2  - Advances in Direct Methods for Materials and Structures
N2  - In this paper we propose a stochastic programming method to analyse limit and shakedown of structures under uncertainty condition of strength. Based on the duality theory, the shakedown load multiplier formulated by the kinematic theorem is proved actually to be the dual form of the shakedown load multiplier formulated by static theorem. In this investigation a dual chance constrained programming algorithm is developed to calculate simultaneously both the upper and lower bounds of the plastic collapse limit and the shakedown limit. The edge-based smoothed finite element method (ES-FEM) with three-node linear triangular elements is used for structural analysis.
Y1  - 2017
SN  - 978-3-319-59810-9
U6  - https://doi.org/10.1007/978-3-319-59810-9_6
SP  - 85
EP  - 103
PB  - Springer
CY  - Cham
ER  - 
TY  - CHAP
A1  - Duong, Minh Tuan
A1  - Nguyen, Nhu Huynh
A1  - Staat, Manfred
T1  - Physical response of hyperelastic models for composite materials and soft tissues
T2  - Advances in Composite Material
Y1  - 2017
SN  - 978-1-61896-300-0 (Hardcover), 978-1-61896-299-7 (Paperback)
N1  - Chapter 5
PB  - Scientific Research Publishing
CY  - Wuhan
ER  - 
TY  - CHAP
A1  - Digel, Ilya
A1  - Sadykov, R.
A1  - Temiz Artmann, Aysegül
A1  - Artmann, Gerhard
T1  - Changes in intestinal microflora in rats induced by oral exposure to low lead (II) concentrations
T2  - Lead Exposure and Poisoning: Clinical Symptoms, Medical Management and Preventive Strategies
Y1  - 2015
SN  - 9781634826990
SP  - 75
EP  - 99
PB  - Nova Science Publ.
ER  - 
TY  - CHAP
A1  - Tran, Thanh Ngoc
A1  - Staat, Manfred
T1  - Uncertainty multimode failure and shakedown analysis of shells
T2  - Direct methods for limit and shakedown analysis of structures / eds. Paolo Fuschi ...
N2  - This paper presents a numerical procedure for reliability analysis of thin plates and shells with respect to plastic collapse or to inadaptation. The procedure involves a deterministic shakedown analysis for each probabilistic iteration, which is based on the upper bound approach and the use of the exact Ilyushin yield surface. Probabilistic shakedown analysis deals with uncertainties originated from the loads, material strength and thickness of the shell. Based on a direct definition of the limit state function, the calculation of the failure probability may be efficiently solved by using the First and Second Order Reliability Methods (FORM and SORM). The problem of reliability of structural systems (series systems) is handled by the application of a special technique which permits to find all the design points corresponding to all the failure modes. Studies show, in this case, that it improves considerably the FORM and SORM results.
KW  - Limit analysis
KW  - Shakedown analysis
KW  - Reliability analysis
KW  - Multimode failure
KW  - Non-linear optimization
Y1  - 2015
SN  - 978-3-319-12927-3 (print) ; 978-3-319-12928-0 (online)
U6  - https://doi.org/10.1007/978-3-319-12928-0_14
SP  - 279
EP  - 298
PB  - Springer
CY  - Cham
ER  - 
TY  - CHAP
A1  - Knott, Thomas C.
A1  - Sofronia, Raluca E.
A1  - Gerressen, Marcus
A1  - Law, Yuen
A1  - Davidescu, Arjana
A1  - Savii, George G.
A1  - Gatzweiler, Karl-Heinz
A1  - Staat, Manfred
A1  - Kuhlen, Torsten W.
T1  - Preliminary bone sawing model for a virtual reality-based training simulator of bilateral sagittal split osteotomy
T2  - Biomedical simulation : 6th International Symposium, ISBMS 2014, Strasbourg, France, October 16-17, 2014 : proceedings (Lecture notes in computer science : vol. 8789)
N2  - Successful bone sawing requires a high level of skill and experience, which could be gained by the use of Virtual Reality-based simulators. A key aspect of these medical simulators is realistic force feedback. The aim of this paper is to model the bone sawing process in order to develop a valid training simulator for the bilateral sagittal split osteotomy, the most often applied corrective surgery in case of a malposition of the mandible. Bone samples from a human cadaveric mandible were tested using a designed experimental system. Image processing and statistical analysis were used for the selection of four models for the bone sawing process. The results revealed a polynomial dependency between the material removal rate and the applied force. Differences between the three segments of the osteotomy line and between the cortical and cancellous bone were highlighted.
KW  - Bone sawing
KW  - virtual reality
KW  - training simulator
Y1  - 2014
SN  - 978-3-319-12057-7 (Online)
SN  - 978-3-319-12056-0 (Print)
U6  - https://doi.org/10.1007/978-3-319-12057-7_1
SP  - 1
EP  - 10
PB  - Springer
CY  - Cham
ER  - 
TY  - CHAP
A1  - Frotscher, Ralf
A1  - Goßmann, Matthias
A1  - Raatschen, Hans-Jürgen
A1  - Temiz Artmann, Aysegül
A1  - Staat, Manfred
T1  - Simulation of cardiac cell-seeded membranes using the edge-based smoothed FEM
T2  - Shell and membrane theories in mechanics and biology. (Advanced structured materials ; 45)
N2  - We present an electromechanically coupled Finite Element model for cardiac tissue. It bases on the mechanical model for cardiac tissue of Hunter et al. that we couple to the McAllister-Noble-Tsien electrophysiological model of purkinje fibre cells. The corresponding system of ordinary differential equations is implemented on the level of the constitutive equations in a geometrically and physically nonlinear version of the so-called edge-based smoothed FEM for plates. Mechanical material parameters are determined from our own pressure-deflection experimental setup. The main purpose of the model is to further examine the experimental results not only on mechanical but also on electrophysiological level down to ion channel gates. Moreover, we present first drug treatment simulations and validate the model with respect to the experiments.
Y1  - 2015
SN  - 978-3-319-02534-6 ; 978-3-319-02535-3
SP  - 187
EP  - 212
PB  - Springer
CY  - Heidelberg
ER  - 
TY  - CHAP
A1  - Macdonald, Malcolm
A1  - McGrath, C.
A1  - Appourchaux, T.
A1  - Dachwald, Bernd
A1  - Finsterle, W.
A1  - Gizon, L.
A1  - Liewer, P. C.
A1  - McInnes, Colin R.
A1  - Mengali, G.
A1  - Seboldt, W.
A1  - Sekii, T.
A1  - Solanki, S. K.
A1  - Velli, M.
A1  - Wimmer-Schweingruber, R. F.
A1  - Spietz, Peter
A1  - Reinhard, Ruedeger
ED  - Macdonald, Malcolm
T1  - Gossamer roadmap technology reference study for a solar polar mission
T2  - Advances in solar sailing
N2  - A technology reference study for a solar polar mission is presented. The study uses novel analytical methods to quantify the mission design space including the required sail performance to achieve a given solar polar observation angle within a given timeframe and thus to derive mass allocations for the remaining spacecraft sub-systems, that is excluding the solar sail sub-system. A parametric, bottom-up, system mass budget analysis is then used to establish the required sail technology to deliver a range of science payloads, and to establish where such payloads can be delivered to within a given timeframe. It is found that a solar polar mission requires a solar sail of side-length 100–125 m to deliver a ‘sufficient value’ minimum science payload, and that a 2.5 μm sail film substrate is typically required, however the design is much less sensitive to the boom specific mass.
Y1  - 2014
SN  - 978-3-642-34906-5
U6  - https://doi.org/10.1007/978-3-642-34907-2_17
SP  - 243
EP  - 257
PB  - Springer
CY  - Berlin, Heidelberg
ER  - 
TY  - CHAP
A1  - McInnes, Colin R.
A1  - Bothmer, Volker
A1  - Dachwald, Bernd
A1  - Geppert, Ulrich R. M. E.
A1  - Heiligers, Jeannette
A1  - Hilgers, Alan
A1  - Johnson, Les
A1  - Macdonald, Malcolm
A1  - Reinhard, Ruedeger
A1  - Seboldt, Wolfgang
A1  - Spietz, Peter
T1  - Gossamer roadmap technology reference study for a Sub-L1 Space Weather Mission
T2  - Advances in solar sailing
N2  - A technology reference study for a displaced Lagrange point space weather mission is presented. The mission builds on previous concepts, but adopts a strong micro-spacecraft philosophy to deliver a low mass platform and payload which can be accommodated on the DLR/ESA Gossamer-3 technology demonstration mission. A direct escape from Geostationary Transfer Orbit is assumed with the sail deployed after the escape burn. The use of a miniaturized, low mass platform and payload then allows the Gossamer-3 solar sail to potentially double the warning time of space weather events. The mission profile and mass budgets will be presented to achieve these ambitious goals.
Y1  - 2014
SN  - 978-3-642-34906-5 (Print) ; 978-3-642-34907-2 (E-Book)
SP  - 227
EP  - 242
PB  - Springer
CY  - Berlin [u.a.]
ER  - 
TY  - CHAP
A1  - Dachwald, Bernd
A1  - Boehnhardt, Herrmann
A1  - Broj, Ulrich
A1  - Geppert, Ulrich R. M. E.
A1  - Grundmann, Jan-Thimo
A1  - Seboldt, Wolfgang
A1  - Seefeldt, Patric
A1  - Spietz, Peter
A1  - Johnson, Les
A1  - Kührt, Ekkehard
A1  - Mottola, Stefano
A1  - Macdonald, Malcolm
A1  - McInnes, Colin R.
A1  - Vasile, Massimiliano
A1  - Reinhard, Ruedeger
T1  - Gossamer roadmap technology reference study for a multiple NEO Rendezvous Mission
T2  - Advances in solar sailing
N2  - A technology reference study for a multiple near-Earth object (NEO) rendezvous mission with solar sailcraft is currently carried out by the authors of this paper. The investigated mission builds on previous concepts, but adopts a strong micro-spacecraft philosophy based on the DLR/ESA Gossamer technology. The main scientific objective of the mission is to explore the diversity of NEOs. After direct interplanetary insertion, the solar sailcraft should—within less than 10 years—rendezvous three NEOs that are not only scientifically interesting, but also from the point of human spaceight and planetary defense. In this paper, the objectives of the study are outlined and a preliminary potential mission profile is presented.
Y1  - 2014
SN  - 978-3-642-34906-5 (Print) ; 978-3-642-34907-2 (E-Book)
SP  - 211
EP  - 226
PB  - Springer
CY  - Berlin [u.a.]
ER  -