@article{MayerHentschkeHageretal.2017,
  author    = {Mayer, Jan and Hentschke, Reinhard and Hager, Jonathan and Hojdis, Nils and Karimi-Varnaneh, Hossein Ali},
  title     = {A Nano-Mechanical Instability as Primary Contribution to Rolling Resistance},
  series = {Scientific Reports},
  volume    = {7},
  journal   = {Scientific Reports},
  number    = {Article number 11275},
  publisher = {Springer},
  address   = {Berlin},
  issn      = {2045-2322},
  year      = {2017},
  language  = {en}
}
@article{SvaneborgKarimiVarzanehHojdisetal.2018,
  author    = {Svaneborg, Carsten and Karimi-Varzaneh, Hossein Ali and Hojdis, Nils and Fleck, Franz and Everaers, Ralf},
  title     = {Kremer-Grest Models for Universal Properties of Specific Common Polymer Species},
  series = {Soft Condensed Matter},
  journal   = {Soft Condensed Matter},
  number    = {1606.05008},
  year      = {2018},
  abstract  = {The Kremer-Grest (KG) bead-spring model is a near standard in Molecular Dynamic simulations of generic polymer properties. It owes its popularity to its computational efficiency, rather than its ability to represent specific polymer species and conditions. Here we investigate how to adapt the model to match the universal properties of a wide range of chemical polymers species. For this purpose we vary a single parameter originally introduced by Faller and M{\"u}ller-Plathe, the chain stiffness. Examples include polystyrene, polyethylene, polypropylene, cis-polyisoprene, polydimethylsiloxane, polyethyleneoxide and styrene-butadiene rubber. We do this by matching the number of Kuhn segments per chain and the number of Kuhn segments per cubic Kuhn volume for the polymer species and for the Kremer-Grest model. We also derive mapping relations for converting KG model units back to physical units, in particular we obtain the entanglement time for the KG model as function of stiffness allowing for a time mapping. To test these relations, we generate large equilibrated well entangled polymer melts, and measure the entanglement moduli using a static primitive-path analysis of the entangled melt structure as well as by simulations of step-strain deformation of the model melts. The obtained moduli for our model polymer melts are in good agreement with the experimentally expected moduli.},
  language  = {en}
}
@article{WallerBraunHojdisetal.2007,
  author    = {Waller, Mark P. and Braun, Heiko and Hojdis, Nils and B{\"u}hl, Michael},
  title     = {Geometries of Second-Row Transition-Metal Complexes from Density-Functional Theory},
  series = {Journal of Chemical Theory and Computation},
  volume    = {3},
  journal   = {Journal of Chemical Theory and Computation},
  number    = {6},
  issn      = {1549-9626},
  doi       = {10.1021/ct700178y},
  pages     = {2234 -- 2242},
  year      = {2007},
  language  = {en}
}
@article{HagerHentschkeHojdisetal.2015,
  author    = {Hager, Jonathan and Hentschke, Reinhard and Hojdis, Nils and Karimi-Varzaneh, Hossein Ali},
  title     = {Computer Simulation of Particle-Particle Interaction in a Model Polymer Nanocomposite},
  series = {Macromolecules},
  volume    = {48},
  journal   = {Macromolecules},
  number    = {24},
  issn      = {1520-5835},
  doi       = {10.1021/acs.macromol.5b01864},
  pages     = {9039 -- 9049},
  year      = {2015},
  language  = {en}
}
@article{MeyerHentschkeHageretal.2017,
  author    = {Meyer, Jan and Hentschke, Reinhard and Hager, Jonathan and Hojdis, Nils and Karimi-Varzaneh, Hossein Ali},
  title     = {Molecular Simulation of Viscous Dissipation due to Cyclic Deformation of a Silica-Silica Contact in Filled Rubber},
  series = {Macromolecules},
  volume    = {50},
  journal   = {Macromolecules},
  number    = {17},
  issn      = {1520-5835},
  doi       = {10.1021/acs.macromol.7b00947},
  pages     = {6679 -- 6689},
  year      = {2017},
  language  = {en}
}
@article{EveraersKarimiVarzanehFlecketal.2020,
  author    = {Everaers, Ralf and Karimi-Varzaneh, Hossein Ali and Fleck, Franz and Hojdis, Nils and Svaneborg, Carsten},
  title     = {Kremer-Grest Models for Commodity Polymer Melts: Linking Theory, Experiment, and Simulation at the Kuhn Scale},
  series = {Macromolecules},
  volume    = {53},
  journal   = {Macromolecules},
  number    = {6},
  publisher = {ACS Publications},
  address   = {Washington, DC},
  issn      = {1520-5835},
  doi       = {10.1021/acs.macromol.9b02428},
  pages     = {1901 -- 1916},
  year      = {2020},
  abstract  = {The Kremer-Grest (KG) polymer model is a standard model for studying generic polymer properties in molecular dynamics simulations. It owes its popularity to its simplicity and computational efficiency, rather than its ability to represent specific polymers species and conditions. Here we show that by tuning the chain stiffness it is possible to adapt the KG model to model melts of real polymers. In particular, we provide mapping relations from KG to SI units for a wide range of commodity polymers. The connection between the experimental and the KG melts is made at the Kuhn scale, i.e., at the crossover from the chemistry-specific small scale to the universal large scale behavior. We expect Kuhn scale-mapped KG models to faithfully represent universal properties dominated by the large scale conformational statistics and dynamics of flexible polymers. In particular, we observe very good agreement between entanglement moduli of our KG models and the experimental moduli of the target polymers.},
  language  = {en}
}
@article{HorbachStaatPerezVianaetal.2020,
  author    = {Horbach, Andreas and Staat, Manfred and Perez-Viana, Daniel and Simmen, Hans-Peter and Neuhaus, Valentin and Pape, Hans-Christoph and Prescher, Andreas and Ciritsis, Bernhard},
  title     = {Biomechanical in vitro examination of a standardized low-volume tubular femoroplasty},
  series = {Clinical Biomechanics},
  volume    = {80},
  journal   = {Clinical Biomechanics},
  number    = {Art. 105104},
  publisher = {Elsevier},
  address   = {Amsterdam},
  doi       = {10.1016/j.clinbiomech.2020.105104},
  year      = {2020},
  abstract  = {Background Osteoporosis is associated with the risk of fractures near the hip. Age and comorbidities increase the perioperative risk. Due to the ageing population, fracture of the proximal femur also proves to be a socio-economic problem. Preventive surgical measures have hardly been used so far. Methods 10 pairs of human femora from fresh cadavers were divided into control and low-volume femoroplasty groups and subjected to a Hayes fall-loading fracture test. The results of the respective localization and classification of the fracture site, the Singh index determined by computed tomography (CT) examination and the parameters in terms of fracture force, work to fracture and stiffness were evaluated statistically and with the finite element method. In addition, a finite element parametric study with different position angles and variants of the tubular geometry of the femoroplasty was performed. Findings Compared to the control group, the work to fracture could be increased by 33.2\%. The fracture force increased by 19.9\%. The used technique and instrumentation proved to be standardized and reproducible with an average poly(methyl methacrylate) volume of 10.5 ml. The parametric study showed the best results for the selected angle and geometry. Interpretation The cadaver studies demonstrated the biomechanical efficacy of the low-volume tubular femoroplasty. The numerical calculations confirmed the optimal choice of positioning as well as the inner and outer diameter of the tube in this setting. The standardized minimally invasive technique with the instruments developed for it could be used in further comparative studies to confirm the measured biomechanical results.},
  language  = {en}
}
@article{FrankoDuKallweitetal.2020,
  author    = {Franko, Josef and Du, Shengzhi and Kallweit, Stephan and Duelberg, Enno Sebastian and Engemann, Heiko},
  title     = {Design of a Multi-Robot System for Wind Turbine Maintenance},
  series = {Energies},
  volume    = {13},
  journal   = {Energies},
  number    = {10},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {1996-1073},
  doi       = {10.3390/en13102552},
  pages     = {Article 2552},
  year      = {2020},
  abstract  = {The maintenance of wind turbines is of growing importance considering the transition to renewable energy. This paper presents a multi-robot-approach for automated wind turbine maintenance including a novel climbing robot. Currently, wind turbine maintenance remains a manual task, which is monotonous, dangerous, and also physically demanding due to the large scale of wind turbines. Technical climbers are required to work at significant heights, even in bad weather conditions. Furthermore, a skilled labor force with sufficient knowledge in repairing fiber composite material is rare. Autonomous mobile systems enable the digitization of the maintenance process. They can be designed for weather-independent operations. This work contributes to the development and experimental validation of a maintenance system consisting of multiple robotic platforms for a variety of tasks, such as wind turbine tower and rotor blade service. In this work, multicopters with vision and LiDAR sensors for global inspection are used to guide slower climbing robots. Light-weight magnetic climbers with surface contact were used to analyze structure parts with non-destructive inspection methods and to locally repair smaller defects. Localization was enabled by adapting odometry for conical-shaped surfaces considering additional navigation sensors. Magnets were suitable for steel towers to clamp onto the surface. A friction-based climbing ring robot (SMART— Scanning, Monitoring, Analyzing, Repair and Transportation) completed the set-up for higher payload. The maintenance period could be extended by using weather-proofed maintenance robots. The multi-robot-system was running the Robot Operating System (ROS). Additionally, first steps towards machine learning would enable maintenance staff to use pattern classification for fault diagnosis in order to operate safely from the ground in the future.},
  language  = {en}
}
@article{WeberArentMuenchetal.2016,
  author    = {Weber, Tobias and Arent, Jan-Christoph and M{\"u}nch, Lukas and Duhovic, Miro and Balvers, Johannes M.},
  title     = {A fast method for the generation of boundary conditions for thermal autoclave simulation},
  series = {Composites Part A},
  volume    = {88},
  journal   = {Composites Part A},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {1359-835X},
  doi       = {10.1016/j.compositesa.2016.05.036},
  pages     = {216 -- 225},
  year      = {2016},
  abstract  = {Manufacturing process simulation enables the evaluation and improvement of autoclave mold concepts early in the design phase. To achieve a high part quality at low cycle times, the thermal behavior of the autoclave mold can be investigated by means of simulations. Most challenging for such a simulation is the generation of necessary boundary conditions. Heat-up and temperature distribution in an autoclave mold are governed by flow phenomena, tooling material and shape, position within the autoclave, and the chosen autoclave cycle. This paper identifies and summarizes the most important factors influencing mold heat-up and how they can be introduced into a thermal simulation. Thermal measurements are used to quantify the impact of the various parameters. Finally, the gained knowledge is applied to develop a semi-empirical approach for boundary condition estimation that enables a simple and fast thermal simulation of the autoclave curing process with reasonably high accuracy for tooling optimization.},
  language  = {en}
}
@article{WeberArentSteffenetal.2017,
  author    = {Weber, Tobias and Arent, Jan-Christoph and Steffen, Lucas and Balvers, Johannes M. and Duhovic, Miro},
  title     = {Thermal optimization of composite autoclave molds using the shift factor approach for boundary condition estimation},
  series = {Journal of Composite Materials},
  volume    = {51},
  journal   = {Journal of Composite Materials},
  number    = {12},
  publisher = {Sage},
  address   = {London},
  issn      = {1530-793X},
  doi       = {10.1177/0021998317699868},
  pages     = {1753 -- 1767},
  year      = {2017},
  language  = {en}
}
@article{WeberRuffStahl2017,
  author    = {Weber, Tobias and Ruff-Stahl, Hans-Joachim K.},
  title     = {Advances in Composite Manufacturing of Helicopter Parts},
  series = {International Journal of Aviation, Aeronautics, and Aerospace},
  volume    = {4},
  journal   = {International Journal of Aviation, Aeronautics, and Aerospace},
  number    = {1},
  issn      = {2374-6793},
  doi       = {10.15394/ijaaa.2017.1153},
  year      = {2017},
  language  = {en}
}
@article{OttenWeberArent2018,
  author    = {Otten, Dennis and Weber, Tobias and Arent, Jan-Christoph},
  title     = {Manufacturing Process Simulation - On Its Way to Industrial Application},
  series = {International Journal of Aviation, Aeronautics, and Aerospace},
  volume    = {5},
  journal   = {International Journal of Aviation, Aeronautics, and Aerospace},
  number    = {2},
  publisher = {Embry-Riddle Aeronautical University},
  address   = {Daytona Beach, Fla.},
  issn      = {2374-6793},
  doi       = {10.15394/ijaaa.2018.1217},
  year      = {2018},
  abstract  = {Manufacturing process simulation (MPS) has become more and more important for aviation and the automobile industry. A highly competitive market requires the use of high performance metals and composite materials in combination with reduced manufacturing cost and time as well as a minimization of the time to market for a new product. However, the use of such materials is expensive and requires sophisticated manufacturing processes. An experience based process and tooling design followed by a lengthy trial-and-error optimization is just not contemporary anymore. Instead, a tooling design process aided by simulation is used more often. This paper provides an overview of the capabilities of MPS in the fields of sheet metal forming and prepreg autoclave manufacturing of composite parts summarizing the resulting benefits for tooling design and manufacturing engineering. The simulation technology is explained briefly in order to show several simplification and optimization techniques for developing industrialized simulation approaches. Small case studies provide examples of an efficient application on an industrial scale.},
  language  = {en}
}
@article{WeberEnglhardArentetal.2019,
  author    = {Weber, Tobias and Englhard, Markus and Arent, Jan-Christoph and Hausmann, Joachim},
  title     = {An experimental characterization of wrinkling generated during prepreg autoclave manufacturing using caul plates},
  series = {Journal of Composite Materials},
  volume    = {53},
  journal   = {Journal of Composite Materials},
  number    = {26-27},
  issn      = {1530-793X},
  doi       = {10.1177/0021998319846556},
  pages     = {3757 -- 3773},
  year      = {2019},
  language  = {en}
}
@article{HailerWeberNevelingetal.2020,
  author    = {Hailer, Benjamin and Weber, Tobias and Neveling, Sebastian and Dera, Samuel and Arent, Jan-Christoph and Middendorf, Peter},
  title     = {Development of a test device to determine the frictional behavior between honeycomb and prepreg layers under realistic manufacturing conditions},
  series = {Journal of Sandwich Structures \& Materials},
  journal   = {Journal of Sandwich Structures \& Materials},
  number    = {Volume 23, Issue 7},
  publisher = {Sage},
  address   = {London},
  issn      = {1530-7972},
  doi       = {10.1177/1099636220923986},
  pages     = {3017 -- 3043},
  year      = {2020},
  abstract  = {In the friction tests between honeycomb with film adhesive and prepreg, the relative displacement occurs between the film adhesive and the prepreg. The film adhesive does not shift relative to the honeycomb. This is consistent with the core crush behavior where the honeycomb moves together with the film adhesive, as can be seen in Figure 2(a). The pull-through forces of the friction measurements between honeycomb and prepreg at 1 mm deformation are plotted in Figure 17(a). While the friction at 100°C is similar to the friction at 120°C, it decreases significantly at 130°C and exhibits a minimum at 140°C. At 150°C, the friction rises again slightly and then sharply at 160°C. Since the viscosity of the M18/1 prepreg resin drops significantly before it cures [23], the minimum friction at 140°C could result from a minimum viscosity of the mixture of prepreg resin and film adhesive before the bond subsequently cures. Figure 17(b) shows the mean value curve of the friction measurements at 140°C. The error bars, which represent the standard deviation, reveal the good repeatability of the tests. The force curve is approximately horizontal between 1 mm and 2 mm. The friction then slightly rises. As with interlaminar friction measurements, this could be due to the fact that resin is removed by friction and the proportion of boundary lubrication increases. Figure 18 shows the surfaces after the friction measurement. The honeycomb cell walls are clearly visible in the film adhesive. There are areas where the film adhesive is completely removed and the carrier material of the film adhesive becomes visible. In addition, the viscosity of the resin changes as the curing progresses during the friction test. This can also affect the force-displacement curve.},
  language  = {en}
}
@article{EngelnMuellges1982,
  author    = {Engeln-M{\"u}llges, Gisela},
  title     = {Entartungsbedingungen f{\"u}r Gleitfl{\"a}chennomogramme und Nomographierbarkeitsbedingungen f{\"u}r Fluchtebenennomogramme},
  series = {ZAMM - Journal of Applied Mathematics and Mechanics / Zeitschrift f{\"u}r Angewandte Mathematik und Mechanik},
  volume    = {62},
  journal   = {ZAMM - Journal of Applied Mathematics and Mechanics / Zeitschrift f{\"u}r Angewandte Mathematik und Mechanik},
  number    = {2},
  issn      = {1521-4001},
  doi       = {10.1002/zamm.19820620203},
  pages     = {77 -- 93},
  year      = {1982},
  language  = {de}
}
@article{KhayyamJamaliBabHadiasharetal.2020,
  author    = {Khayyam, Hamid and Jamali, Ali and Bab-Hadiashar, Alireza and Esch, Thomas and Ramakrishna, Seeram and Jalil, Mahdi and Naebe, Minoo},
  title     = {A Novel Hybrid Machine Learning Algorithm for Limited and Big Data Modelling with Application in Industry 4.0},
  series = {IEEE Access},
  journal   = {IEEE Access},
  publisher = {IEEE},
  address   = {New York, NY},
  isbn      = {2169-3536},
  doi       = {10.1109/ACCESS.2020.2999898},
  pages     = {1 -- 12},
  year      = {2020},
  abstract  = {To meet the challenges of manufacturing smart products, the manufacturing plants have been radically changed to become smart factories underpinned by industry 4.0 technologies. The transformation is assisted by employment of machine learning techniques that can deal with modeling both big or limited data. This manuscript reviews these concepts and present a case study that demonstrates the use of a novel intelligent hybrid algorithms for Industry 4.0 applications with limited data. In particular, an intelligent algorithm is proposed for robust data modeling of nonlinear systems based on input-output data. In our approach, a novel hybrid data-driven combining the Group-Method of Data-Handling and Singular-Value Decomposition is adapted to find an offline deterministic model combined with Pareto multi-objective optimization to overcome the overfitting issue. An Unscented-Kalman-Filter is also incorporated to update the coefficient of the deterministic model and increase its robustness against data uncertainties. The effectiveness of the proposed method is examined on a set of real industrial measurements.},
  language  = {en}
}
@article{RauschHarbrechtKahmannetal.2020,
  author    = {Rausch, Valentin and Harbrecht, Andreas and Kahmann, Stephanie Lucina and Fenten, Thomas and Jovanovic, Nebojsa and Hackl, Michael and M{\"u}ller, Lars P. and Staat, Manfred and Wegmann, Kilian},
  title     = {Osteosynthesis of Phalangeal Fractures: Biomechanical Comparison of Kirschner Wires, Plates, and Compression Screws},
  series = {The Journal of Hand Surgery},
  volume    = {45},
  journal   = {The Journal of Hand Surgery},
  number    = {10},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0363-5023},
  doi       = {10.1016/j.jhsa.2020.04.010},
  pages     = {987.e1 -- 987.e8},
  year      = {2020},
  abstract  = {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.},
  language  = {en}
}
@article{RegerKuhnhenneEbbertetal.2020,
  author    = {Reger, Vitali and Kuhnhenne, Markus and Ebbert, Thiemo and Hachul, Helmut and Blanke, Tobias and D{\"o}ring, Bernd},
  title     = {Nutzung erneuerbarer Energien durch thermische Aktivierung von Komponenten aus Stahl},
  series = {Stahlbau},
  volume    = {2020},
  journal   = {Stahlbau},
  number    = {Volume 89, Issue 6512-519},
  publisher = {Ernst \& Sohn},
  address   = {Berlin},
  issn      = {1437-1049},
  doi       = {10.1002/stab.202000031},
  pages     = {512 -- 519},
  year      = {2020},
  abstract  = {Die Versorgung von Neubauten soll m{\"o}glichst weitgehend unabh{\"a}ngig von fossilen Energietr{\"a}gern erfolgen. Erneuerbare Energien spielen daf{\"u}r eine gewichtige Rolle. Eine gute M{\"o}glichkeit, erneuerbare Energien ohne viel zus{\"a}tzlichen Aufwand nutzbar zu machen, ist, bereits vorhandenen Komponenten im Geb{\"a}ude zus{\"a}tzliche Funktionen zu geben. Hier kann bspw. die Fassade oder das Dach solarthermisch aktiviert oder durch Fotovoltaikmodule erg{\"a}nzt werden. Auch Tiefgr{\"u}ndungen k{\"o}nnen neben der statischen Funktion noch eine geothermische Funktion zur Aufnahme oder Abgabe von W{\"a}rme erhalten. Neben der Erzeugung bietet sich auch f{\"u}r die Verteilung der W{\"a}rme oder K{\"a}lte im Geb{\"a}ude die Integration in Bauteile an. Hier kann bspw. der Boden durch eine Fußbodenheizung oder die Decke durch Deckenstrahlplatten aktiviert werden. Im Rahmen der Ver{\"o}ffentlichung wird auf die thermische Aktivierung von Stahlkomponenten eingegangen. Es wird eine L{\"o}sung vorgestellt, die vorgeh{\"a}ngte hinterl{\"u}ftete Stahlfassade (VHF) solarthermisch zu aktivieren. Außerdem werden zwei M{\"o}glichkeiten zur geothermischen Aktivierung von Tiefgr{\"u}ndungen mittels Stahlpf{\"a}hlen gezeigt. Zuletzt wird ein System zur thermischen Aktivierung von Stahltrapezprofilen an der Decke erl{\"a}utert, welches W{\"a}rme zuf{\"u}hren oder bei Bedarf abf{\"u}hren kann.},
  language  = {de}
}
@article{EdipSesovButenwegetal.2018,
  author    = {Edip, K. and Sesov, V. and Butenweg, Christoph and Bojadjieva, J.},
  title     = {Development of coupled numerical model for simulation of multiphase soil},
  series = {Computers and Geotechnics},
  volume    = {96},
  journal   = {Computers and Geotechnics},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0266-352X},
  doi       = {10.1016/j.compgeo.2017.08.016},
  pages     = {118 -- 131},
  year      = {2018},
  abstract  = {In this paper, a coupled multiphase model considering both non-linearities of water retention curves and solid state modeling is proposed. The solid displacements and the pressures of both water and air phases are unknowns of the proposed model. The finite element method is used to solve the governing differential equations. The proposed method is demonstrated through simulation of seepage test and partially consolidation problem. Then, implementation of the model is done by using hypoplasticity for the solid phase and analyzing the fully saturated triaxial experiments. In integration of the constitutive law error controlling is improved and comparisons done accordingly. In this work, the advantages and limitations of the numerical model are discussed.},
  language  = {en}
}
@article{QuittmannAbelAlbrachtetal.2020,
  author    = {Quittmann, Oliver J. and Abel, Thomas and Albracht, Kirsten and Meskemper, Joshua and Foitschik, Tina and Str{\"u}der, Heiko K.},
  title     = {Biomechanics of handcycling propulsion in a 30-min continuous load test at lactate threshold: Kinetics, kinematics, and muscular activity in able-bodied participants},
  series = {European Journal of Applied Physiology},
  journal   = {European Journal of Applied Physiology},
  number    = {120},
  publisher = {Springer},
  address   = {Heidelberg},
  issn      = {1439-6327},
  doi       = {10.1007/s00421-020-04373-x},
  pages     = {1403 -- 1415},
  year      = {2020},
  abstract  = {Purpose This study aims to investigate the biomechanics of handcycling during a continuous load trial (CLT) to assess the mechanisms underlying fatigue in upper body exercise. Methods Twelve able-bodied triathletes performed a 30-min CLT at a power output corresponding to lactate threshold in a racing recumbent handcycle mounted on a stationary ergometer. During the CLT, ratings of perceived exertion (RPE), tangential crank kinetics, 3D joint kinematics, and muscular activity of ten muscles of the upper extremity and trunk were examined using motion capturing and surface electromyography. Results During the CLT, spontaneously chosen cadence and RPE increased, whereas crank torque decreased. Rotational work was higher during the pull phase. Peripheral RPE was higher compared to central RPE. Joint range of motion decreased for elbow-flexion and radial-duction. Integrated EMG (iEMG) increased in the forearm flexors, forearm extensors, and M. deltoideus (Pars spinalis). An earlier onset of activation was found for M. deltoideus (Pars clavicularis), M. pectoralis major, M. rectus abdominis, M. biceps brachii, and the forearm flexors. Conclusion Fatigue-related alterations seem to apply analogously in handcycling and cycling. The most distal muscles are responsible for force transmission on the cranks and might thus suffer most from neuromuscular fatigue. The findings indicate that peripheral fatigue (at similar lactate values) is higher in handcycling compared to leg cycling, at least for inexperienced participants. An increase in cadence might delay peripheral fatigue by a reduced vascular occlusion. We assume that the gap between peripheral and central fatigue can be reduced by sport-specific endurance training.},
  language  = {en}
}