TY - JOUR A1 - Staat, Manfred T1 - Plastic collapse analysis of longitudinally flawed pipes and vessels N2 - Improved collapse loads of thick-walled, crack containing pipes and vessels are suggested. Very deep cracks have a residual strength which is better modelled by a global limit load. In all burst tests, the ductility of pressure vessel steels was sufficiently high whereby the burst pressure could be predicted by limit analysis with no need to apply fracture mechanics. The relative prognosis error increases however, for long and deep defects due to uncertainties of geometry and strength data. KW - Druckbehälter KW - Stahl KW - Druckbelastung KW - Druckbeanspruchung KW - Rohr KW - Rohrbruch KW - Druckbehälter KW - Stahl KW - Druckbelastung KW - Druckbeanspruchung KW - Rohrbruch KW - Fehlerstellen KW - pipes KW - vessels KW - load limit KW - burst tests KW - burst pressure KW - flaw Y1 - 2004 ER - TY - JOUR A1 - Duong, Minh Tuan A1 - Nguyen, Nhu Huynh A1 - Staat, Manfred T1 - Physical response of hyperelastic models for composite materials and soft tissues JF - Asia pacific journal on computational engineering Y1 - 2015 U6 - http://dx.doi.org/10.1186/s40540-015-0015-x SN - 2196-1166 VL - 2 IS - 3 (December 2015) SP - 1 EP - 18 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 - JOUR A1 - Vant, Christianne A1 - Staat, Manfred A1 - Baroud, Gamal T1 - Percutaneous Vertebroplasty: A Review of Two Intraoperative Complications JF - Bioengineering in Cell and Tissue Research / Artmann, Gerhard M. ; Chien, Shu (Eds.) Y1 - 2008 SN - 978-3-540-75408-4 SP - 527 EP - 539 PB - Springer CY - Berlin ER - TY - CHAP A1 - Bhattarai, Aroj A1 - Staat, Manfred ED - Fernandes, P.R. ED - Tavares, J. M. T1 - Pectopexy to repair vaginal vault prolapse: a finite element approach T2 - Proceedings CMBBE 2018 N2 - The vaginal prolapse after hysterectomy (removal of the uterus) is often associated with the prolapse of the vaginal vault, rectum, bladder, urethra or small bowel. Minimally invasive surgery such as laparoscopic sacrocolpopexy and pectopexy are widely performed for the treatment of the vaginal prolapse with weakly supported vaginal vault after hysterectomy using prosthetic mesh implants to support (or strengthen) lax apical ligaments. Implants of different shape, size and polymers are selected depending on the patient’s anatomy and the surgeon’s preference. In this computational study on pectopexy, DynaMesh®-PRP soft, GYNECARE GYNEMESH® PS Nonabsorbable PROLENE® soft and Ultrapro® are tested in a 3D finite element model of the female pelvic floor. The mesh model is implanted into the extraperitoneal space and sutured to the vaginal stump with a bilateral fixation to the iliopectineal ligament at both sides. Numerical simulations are conducted at rest, after surgery and during Valsalva maneuver with weakened tissues modeled by reduced tissue stiffness. Tissues and prosthetic meshes are modeled as incompressible, isotropic hyperelastic materials. The positions of the organs are calculated with respect to the pubococcygeal line (PCL) for female pelvic floor at rest, after repair and during Valsalva maneuver using the three meshes. Y1 - 2018 N1 - 15th International Symposium on Computer Methods in Biomechanics and Biomedical Engineering and 3rd Conference on Imaging and Visualization. CMBBE 2018. 26-29 March 2018, Lisbon, Portugal ER - TY - JOUR A1 - Kohler, Annette A1 - Kirschner-Hermanns, Ruth A1 - Staat, Manfred A1 - Brehmer, Bernhard T1 - Pathogenese, funktionelle und anatomische Aspekte der weiblichen Belastungsinkontinenz T1 - Female stress incontinence: aspects of pathogenesis and functional anatomy JF - Aktuelle Urologie N2 - Der vorliegende Artikel fokussiert sich auf die weibliche Belastungsinkontinenz als Insuffizienz der Speicherfunktion der Blase, auch wenn im klinischen Alltag die Harninkontinenz der Frau häufig verschiedene Ursachen hat und insbesondere eine Belastungsinkontinenz im Alter und bei neurologischer Komorbidität nur selten isoliert vorkommt. Das kleine Becken der Frau ist sowohl als Funktions- als auch als strukturelle Einheit zu betrachten. Dabei unterliegen bei der Frau Blase, Harnröhre, Gebärmutter und Enddarm sowie die muskulären und ligamentösen Strukturen des kleinen Beckens durch Fertilitätsphase, mögliche Schwangerschaften, Geburten und Menopausen-Phase, über das „normale Altern“ hinaus, gravierenden Veränderungen. This article focuses on female stress incontinence in the form of pelvic floor dysfunction and urethral sphincter deficiency, although isolated stress incontinence accounts for less than half of all incontinence cases. Especially in women of old age and those with neurological comorbidities, the causes of incontinence are mostly multifactorial. Also it has to be considered that the female bladder, urethra, uterus and rectum as well as the muscular and ligamentous structures of the female pelvis minor are affected by phases of fertility, possible pregnancies, births and menopause in addition to the normal ageing process. Y1 - 2018 U6 - http://dx.doi.org/10.1055/s-0043-120616 SN - 1438-8820 VL - 49 IS - 1 SP - 47 EP - 51 PB - Thieme CY - Stuttgart ER - TY - JOUR A1 - Rausch, Valentin A1 - Harbrecht, Andreas A1 - Kahmann, Stephanie Lucina A1 - Fenten, Thomas A1 - Jovanovic, Nebojsa A1 - Hackl, Michael A1 - Müller, Lars P. A1 - Staat, Manfred A1 - Wegmann, Kilian T1 - Osteosynthesis of Phalangeal Fractures: Biomechanical Comparison of Kirschner Wires, Plates, and Compression Screws JF - The Journal of Hand Surgery N2 - Purpose The aim of this study was to compare several osteosynthesis techniques (intramedullary headless compression screws, T-plates, and Kirschner wires) for distal epiphyseal fractures of proximal phalanges in a human cadaveric model. Methods A total of 90 proximal phalanges from 30 specimens (index, ring, and middle fingers) were used for this study. After stripping off all soft tissue, a transverse distal epiphyseal fracture was simulated at the proximal phalanx. The 30 specimens were randomly assigned to 1 fixation technique (30 per technique), either a 3.0-mm intramedullary headless compression screw, locking plate fixation with a 2.0-mm T-plate, or 2 oblique 1.0-mm Kirschner wires. Displacement analysis (bending, distraction, and torsion) was performed using optical tracking of an applied random speckle pattern after osteosynthesis. Biomechanical testing was performed with increasing cyclic loading and with cyclic load to failure using a biaxial torsion-tension testing machine. Results Cannulated intramedullary compression screws showed significantly less displacement at the fracture site in torsional testing. Furthermore, screws were significantly more stable in bending testing. Kirschner wires were significantly less stable than plating or screw fixation in any cyclic load to failure test setup. Conclusions Intramedullary compression screws are a highly stable alternative in the treatment of transverse distal epiphyseal phalangeal fractures. Kirschner wires seem to be inferior regarding displacement properties and primary stability. Clinical relevance Fracture fixation of phalangeal fractures using plate osteosynthesis may have the advantage of a very rigid reduction, but disadvantages such as stiffness owing to the more invasive surgical approach and soft tissue irritation should be taken into account. Headless compression screws represent a minimally invasive choice for fixation with good biomechanical properties. Y1 - 2020 U6 - http://dx.doi.org/10.1016/j.jhsa.2020.04.010 SN - 0363-5023 VL - 45 IS - 10 SP - 987.e1 EP - 987.e8 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Jung, Alexander A1 - Müller, Wolfram A1 - Staat, Manfred T1 - Optimization of the flight technique in ski jumping: the influence of wind Y1 - 2019 U6 - http://dx.doi.org/10.1016/j.jbiomech.2019.03.023 IS - Early view PB - Elsevier CY - Amsterdam ER - TY - CHAP A1 - Jung, Alexander A1 - Staat, Manfred A1 - Müller, Wolfram ED - Onate, E. T1 - Optimization of the flight style in ski jumping T2 - 11th World Congress on Computational Mechanics (WCCM XI) ; 5th European Conference on Computational Mechanics (ECCM V) ; 6th European Conference on Computational Fluid Dynamics (ECFD VI) ; July 20 - 25, 2014, Barcelona Y1 - 2014 N1 - Das Paper wurde nach der Konferenz überarbeitet. SP - 799 EP - 810 ER - TY - JOUR A1 - Horbach, Andreas A1 - Staat, Manfred T1 - Optical strain measurement for the modeling of surgical meshes and their porosity JF - Current Directions in Biomedical Engineering N2 - The porosity of surgical meshes makes them flexible for large elastic deformation and establishes the healing conditions of good tissue in growth. The biomechanic modeling of orthotropic and compressible materials requires new materials models and simulstaneoaus fit of deformation in the load direction as well as trannsversely to to load. This nonlinear modeling can be achieved by an optical deformation measurement. At the same time the full field deformation measurement allows the dermination of the change of porosity with deformation. Also the socalled effective porosity, which has been defined to asses the tisssue interatcion with the mesh implants, can be determined from the global deformation of the surgical meshes. Y1 - 2018 U6 - http://dx.doi.org/10.1515/cdbme-2018-0045 SN - 2364-5504 VL - Band 4 IS - 1 SP - 181 EP - 184 PB - De Gruyter CY - Berlin ER -