@inproceedings{SherelkhanAlibekova2024,
  author    = {Sherelkhan, Dinara and Alibekova, Alina},
  title     = {EEM spectroscopy characterization of humic substances of biomedical importance},
  series = {YRA MedTech Symposium (2024)},
  booktitle = {YRA MedTech Symposium (2024)},
  editor    = {Digel, Ilya and Staat, Manfred and Trzewik, J{\"u}rgen and Sielemann, Stefanie and Erni, Daniel and Zylka, Waldemar},
  publisher = {Universit{\"a}t Duisburg-Essen},
  address   = {Duisburg},
  organization    = {MedTech Symposium},
  isbn      = {978-3-940402-65-3},
  doi       = {10.17185/duepublico/81475},
  pages     = {31 -- 32},
  year      = {2024},
  abstract  = {Humic substances possess distinctive chemical features enabling their use in many advanced applications, including biomedical fields. No chemicals in nature have the same combination of specific chemical and biological properties as humic substances. Traditional medicine and modern research have demonstrated that humic substances from different sources possess immunomodulatory and anti-inflammatory properties, which makes them suitable for the prevention and treatment of chronic dermatoses, allergic rhinitis, atopic dermatitis, and other conditions characterized by inflammatory and allergic responses [1-4]. The use of humic compounds as agentswith antifungal and antiviral properties shows great potential [5-7].},
  language  = {en}
}
@inproceedings{SimsekKrauseEngelmann2024,
  author    = {Simsek, Beril and Krause, Hans-Joachim and Engelmann, Ulrich M.},
  title     = {Magnetic biosensing with magnetic nanoparticles: Simulative approach to predict signal intensity in frequency mixing magnetic detection},
  series = {YRA MedTech Symposium (2024)},
  booktitle = {YRA MedTech Symposium (2024)},
  editor    = {Digel, Ilya and Staat, Manfred and Trzewik, J{\"u}rgen and Sielemann, Stefanie and Erni, Daniel and Zylka, Waldemar},
  publisher = {Universit{\"a}t Duisburg-Essen},
  address   = {Duisburg},
  organization    = {MedTech Symposium},
  isbn      = {978-3-940402-65-3},
  doi       = {10.17185/duepublico/81475},
  pages     = {27 -- 28},
  year      = {2024},
  abstract  = {Magnetic nanoparticles (MNP) are investigated with great interest for biomedical applications in diagnostics (e.g. imaging: magnetic particle imaging (MPI)), therapeutics (e.g. hyperthermia: magnetic fluid hyperthermia (MFH)) and multi-purpose biosensing (e.g. magnetic immunoassays (MIA)). What all of these applications have in common is that they are based on the unique magnetic relaxation mechanisms of MNP in an alternating magnetic field (AMF). While MFH and MPI are currently the most prominent examples of biomedical applications, here we present results on the relatively new biosensing application of frequency mixing magnetic detection (FMMD) from a simulation perspective. In general, we ask how the key parameters of MNP (core size and magnetic anisotropy) affect the FMMD signal: by varying the core size, we investigate the effect of the magnetic volume per MNP; and by changing the effective magnetic anisotropy, we study the MNPs' flexibility to leave its preferred magnetization direction. From this, we predict the most effective combination of MNP core size and magnetic anisotropy for maximum signal generation.},
  language  = {en}
}
@book{StaatDigelTrzewiketal.2024,
  author    = {Staat, Manfred and Digel, Ilya and Trzewik, J{\"u}rgen and Sielemann, Stefanie and Erni, Daniel and Zylka, Waldemar},
  title     = {Symposium Proceedings; 4th YRA MedTech Symposium 2024 : February 1 / 2024 / FH Aachen},
  publisher = {Universit{\"a}t Duisburg-Essen},
  address   = {Duisburg},
  organization    = {MedTech Symposium},
  isbn      = {978-3-940402-65-3},
  doi       = {10.17185/duepublico/81475},
  pages     = {40 Seiten},
  year      = {2024},
  language  = {en}
}
@inproceedings{Tepecik2024,
  author    = {Tepecik, Atakan},
  title     = {AstroBioLab: Review of technical and bioanalytical approaches},
  series = {YRA MedTech Symposium (2024)},
  booktitle = {YRA MedTech Symposium (2024)},
  editor    = {Digel, Ilya and Staat, Manfred and Trzewik, J{\"u}rgen and Sielemann, Stefanie and Erni, Daniel and Zylka, Waldemar},
  publisher = {Universit{\"a}t Duisburg-Essen},
  address   = {Duisburg},
  organization    = {MedTech Symposium},
  isbn      = {978-3-940402-65-3},
  doi       = {10.17185/duepublico/81475},
  pages     = {33 -- 34},
  year      = {2024},
  abstract  = {This study presents the concept of AstroBioLab, an autonomous astrobiological field laboratory tailored for the exploration of (sub)glacial habitats. AstroBioLab is an integral component of the TRIPLE (Technologies for Rapid Ice Penetration and subglacial Lake Exploration) DLR-funded project, aimed at advancing astrobiology research through the development and deployment of innovative technologies. AstroBioLab integrates diverse measurement techniques such as fluorescence microscopy, DNA sequencing and fluorescence spectrometry, while leveraging microfluidics for efficient sample delivery and preparation.},
  language  = {en}
}
@article{Timme2024,
  author    = {Timme, Michael},
  title     = {Kaufvertrag: Das Zusammentreffen von Beschaffenheitsvereinbarung und Gew{\"a}hrleistungsausschluss - ein Spannungsverh{\"a}ltnis},
  series = {Monatsschrift f{\"u}r Deutsches Recht},
  volume    = {78},
  journal   = {Monatsschrift f{\"u}r Deutsches Recht},
  number    = {12},
  publisher = {Verlag Dr. Otto Schmidt},
  address   = {K{\"o}ln},
  issn      = {2194-4202 (online)},
  doi       = {10.9785/mdtr-2024-781203},
  pages     = {745 -- 748},
  year      = {2024},
  abstract  = {Wer A sagt, muss zumindest im Kaufrecht nicht immer B sagen: Es kommt nicht selten vor, dass sich in einem Kaufvertrag einerseits ein wirksamer Ausschluss der Gew{\"a}hrleistung des Verk{\"a}ufers f{\"u}r Sachm{\"a}ngel findet, die Parteien aber andererseits gleichwohl eine Beschaffenheitsvereinbarung f{\"u}r bestimmte Eigenschaften vertraglich festlegen. In diesem Problemfeld f{\"u}hrt eine aktuelle Entscheidung des BGH zu weiteren Kl{\"a}rungen f{\"u}r die Praxis (BGH, Urt. v. 10.4.2024 - VIII ZR 161/23, MDR 2024, 706). Der folgende Beitrag setzt sich mit den vielf{\"a}ltigen Aspekten der Entscheidung auseinander und erl{\"a}utert, aus welchen Gr{\"u}nden der BGH dem K{\"a}ufer einige goldene Br{\"u}cken f{\"u}r einen Schadensersatzanspruch gebaut hat.},
  language  = {de}
}
@article{TurdumamatovBeldaHeuermann2024,
  author    = {Turdumamatov, Samat and Belda, Aljoscha and Heuermann, Holger},
  title     = {Shaping a decoupled atmospheric pressure microwave plasma with antenna structures, Maxwell's equations, and boundary conditions},
  series = {IEEE Transactions on Plasma Science},
  journal   = {IEEE Transactions on Plasma Science},
  number    = {Early Access},
  publisher = {IEEE},
  issn      = {0093-3813 (Print)},
  doi       = {10.1109/TPS.2024.3383589},
  pages     = {1 -- 9},
  year      = {2024},
  abstract  = {This article addresses the need for an innovative technique in plasma shaping, utilizing antenna structures, Maxwell's laws, and boundary conditions within a shielded environment. The motivation lies in exploring a novel approach to efficiently generate high-energy density plasma with potential applications across various fields. Implemented in an E01 circular cavity resonator, the proposed method involves the use of an impedance and field matching device with a coaxial connector and a specially optimized monopole antenna. This setup feeds a low-loss cavity resonator, resulting in a high-energy density air plasma with a surface temperature exceeding 3500 o C, achieved with a minimal power input of 80 W. The argon plasma, resembling the shape of a simple monopole antenna with modeled complex dielectric values, offers a more energy-efficient alternative compared to traditional, power-intensive plasma shaping methods. Simulations using a commercial electromagnetic (EM) solver validate the design's effectiveness, while experimental validation underscores the method's feasibility and practical implementation. Analyzing various parameters in an argon atmosphere, including hot S -parameters and plasma beam images, the results demonstrate the successful application of this technique, suggesting its potential in coating, furnace technology, fusion, and spectroscopy applications.},
  language  = {en}
}
@incollection{Ulke2024,
  author    = {Ulke, Bernd},
  title     = {Bauwirtschaft},
  series = {Zahlentafeln f{\"u}r den Baubetrieb},
  booktitle = {Zahlentafeln f{\"u}r den Baubetrieb},
  editor    = {Krause, Thomas and Ulke, Bernd and Ferger, Martin},
  publisher = {Springer Vieweg},
  address   = {Wiesbaden},
  isbn      = {978-3-658-41329-3 (Print)},
  doi       = {10.1007/978-3-658-41330-9_4},
  pages     = {17 -- 261},
  year      = {2024},
  abstract  = {Die Leistungen der Bauwirtschaft und deren wirtschaftliche Bedeutung in Deutschland werden anhand einer Vielzahl statistischer Daten verdeutlicht. Die im Vergleich zu anderen Wirtschaftsbereichen auftretenden branchenspezifischen Besonderheiten der Bauwirtschaft werden anhand von verschiedenen Kriterien herausgearbeitet. Das Zusammenspiel der einzelnen Akteure des Sektors und die dabei sich ergebenden bzw. zu beachtenden Rechts- und Vertragsgrundlagen werden dargestellt. Aufgrund der meist erheblichen H{\"o}he des eingesetzten Kapitals werden auch notwendige Formen der Risikoabsicherungen und der in der Branche {\"u}blichen und teilweise vorgeschriebenen Versicherungsm{\"o}glichkeiten angesprochen.},
  language  = {de}
}
@incollection{Ulke2024,
  author    = {Ulke, Bernd},
  title     = {{\"O}ffentliches Baurecht, Ausschreibung und Vergabe},
  series = {Zahlentafeln f{\"u}r den Baubetrieb},
  booktitle = {Zahlentafeln f{\"u}r den Baubetrieb},
  editor    = {Krause, Thomas and Ulke, Bernd and Ferger, Martin},
  publisher = {Springer Vieweg},
  address   = {Wiesbaden},
  isbn      = {978-3-658-41329-3 (Print)},
  doi       = {10.1007/978-3-658-41330-9_5},
  pages     = {263 -- 297},
  year      = {2024},
  abstract  = {Durch das {\"o}ffentliche Baurecht werden die Zul{\"a}ssigkeit, die Grenzen, die Ordnung und die F{\"o}rderung der baulichen Nutzung des Bodens geregelt. Die Ausschreibung und die Vergabe sind von essenzieller Bedeutung f{\"u}r ein Bauvorhaben und werden deshalb in der HOAI mit zwei Leistungsphasen abgebildet: n{\"a}mlich mit der Leistungsphase 6 Vorbereitung der Vergabe sowie der Leistungsphase 7 Mitwirkung bei der Vergabe. Im Zuge der Ausschreibung und der Vergabe werden die f{\"u}r den AG anfallenden Kosten festgelegt und bilden somit die letzte gr{\"o}ßere Stellschraube f{\"u}r Preiseinsparungen.},
  language  = {de}
}
@incollection{Ulke2024,
  author    = {Ulke, Bernd},
  title     = {Boden, Baugrube, Verbau},
  series = {Zahlentafeln f{\"u}r den Baubetrieb},
  booktitle = {Zahlentafeln f{\"u}r den Baubetrieb},
  editor    = {Krause, Thomas and Ulke, Bernd and Ferger, Martin},
  publisher = {Springer Vieweg},
  address   = {Wiesbaden},
  isbn      = {978-3-658-41329-3 (Print)},
  doi       = {10.1007/978-3-658-41330-9_9},
  pages     = {499 -- 658},
  year      = {2024},
  abstract  = {Die L{\"o}sung den Baugrund betreffender Fragestellungen beginnen i. d. R. mit der Durchf{\"u}hrung von Baugrunderkundungen, um alle notwendigen Parameter zu erhalten, die f{\"u}r die Planung und Durchf{\"u}hrung von Bauvorhaben notwendig sind. Im Folgenden werden die wichtigsten Erkundungen in Abh{\"a}ngigkeit der erforderlichen G{\"u}teklasse der Proben beschrieben und vorgestellt.},
  language  = {de}
}
@incollection{Ulke2024,
  author    = {Ulke, Bernd},
  title     = {Kalkulation},
  series = {Zahlentafeln f{\"u}r den Baubetrieb},
  booktitle = {Zahlentafeln f{\"u}r den Baubetrieb},
  editor    = {Krause, Thomas and Ulke, Bernd and Ferger, Martin},
  publisher = {Springer Vieweg},
  address   = {Wiesbaden},
  isbn      = {978-3-658-41329-3 (Print)},
  doi       = {10.1007/978-3-658-41330-9_12},
  pages     = {801 -- 909},
  year      = {2024},
  abstract  = {Das Kapitel behandelt die Kosten- und Preisermittlung, die Kostenvorgabe und Kostenkontrolle. Der Angebotspreis wird aufgeschl{\"u}sselt in die Einzelkosten der Teilleistungen, die Baustellengemeinkosten, die Allgemeinen Gesch{\"a}ftskosten und einen Zuschlag f{\"u}r Wagnis und Gewinn. Auf der Basis der Angebotskalkulation werden die Vorgaben f{\"u}r die Kostenkontrolle entwickelt.},
  language  = {de}
}
@incollection{Ulke2024,
  author    = {Ulke, Bernd},
  title     = {Privates Baurecht und Nachtragsmanagement},
  series = {Zahlentafeln f{\"u}r den Baubetrieb},
  booktitle = {Zahlentafeln f{\"u}r den Baubetrieb},
  editor    = {Krause, Thomas and Ulke, Bernd and Ferger, Martin},
  publisher = {Springer Vieweg},
  address   = {Wiesbaden},
  isbn      = {978-3-658-41329-3 (Print)},
  doi       = {10.1007/978-3-658-41330-9_3},
  pages     = {149 -- 216},
  year      = {2024},
  abstract  = {Kein Bauvorhaben sollte realisiert werden, ohne dass es auf einer vertraglichen Grundlage zwischen Auftraggeber und Auftragnehmer fußt. Diese vertragliche Grundlage zu kennen ist essenziell, um dementsprechend handeln zu k{\"o}nnen. Denn nur wer seine eigenen Rechte und auch Pflichten kennt, kann sich auf diese berufen.},
  language  = {de}
}
@masterthesis{vanderBeek2024,
  type      = {Bachelor Thesis},
  author    = {van der Beek, Lucas},
  title     = {PRO+SOUND : Kombinationsprodukt bestehend aus Lautsprecher und Projektor},
  publisher = {FH Aachen},
  address   = {Aachen},
  pages     = {105 Seiten},
  year      = {2024},
  abstract  = {PRO+SOUND ist ein tragbares Kombinationsprodukt, bestehend aus Lautsprecher und Projektor, das sowohl privat zum streamen von Filmen, Serien, Musik und Videospielen als auch professionell als Pr{\"a}sentationsger{\"a}t in H{\"o}rs{\"a}len und Konferenzr{\"a}umen genutzt werden kann. Projektoren und Beamer sind groß, schwer, unhandlich und nicht mehr zeitgem{\"a}ß. Die Bedienung der meisten Beamer ist veraltet und kaum digitalisiert. PRO+SOUND l{\"o}st diese Schwachstellen in einem kompakten Produkt und macht das streamen von Inhalten m{\"u}helos und kabellos. Das geringe Gewicht und der kompakte Formfaktor macht die Mitnahme f{\"u}r unterwegs problemlos m{\"o}glich.},
  language  = {de}
}
@masterthesis{Vervekina2024,
  type      = {Bachelor Thesis},
  author    = {Vervekina, Tatyana},
  title     = {Designing for Focus : ein Hilfsmittelsystem f{\"u}r Kinder mit AD(H)S},
  publisher = {FH Aachen},
  address   = {Aachen},
  pages     = {113 Seiten},
  year      = {2024},
  abstract  = {Das Projekt widmet sich dem Thema der Aufmerksamkeitsdefizit-Hyperaktivit{\"a}tsst{\"o}rung (ADHS) und Aufmerksamkeitsdefizitst{\"o}rung (ADS) im Kindesalter. Es setzt sich dabei mit den t{\"a}glichen Herausforderungen auseinander, mit denen diese Kinder sowohl im Lernprozess als auch in der famili{\"a}ren Beziehungsdynamik konfrontiert sind. Der entwickelte Konzentrationsbegleiter und das dazugeh{\"o}rige Set basieren auf einer lerntherapeutischen Idee, die ein Gleichgewicht zwischen Konzentration und Entspannung erschafft. Das Gesamtsystem „MonKo" bietet mit dem Konzentrationsbegleiter Unterst{\"u}tzung bei der Alltagsplanung, Priorisierung von Aufgaben und dem Umgang mit Reizen. Der Entspannungsteil des Sets pr{\"a}sentiert sich als „Schatzkiste" mit sensorischen Spielzeugen und ist individuell von Therapeut:innen und Lehrkr{\"a}ften an die Bed{\"u}rfnisse der Kinder anpassbar. Der Konzentrationsbegleiter in der Optik eines liebevollen Monsters soll den Kindern helfen, mit den Herausforderungen neuroatypischen Verhaltens umzugehen und erfolgreich in Schule und Alltag zu sein.},
  language  = {de}
}
@article{WindmuellerSchapsZantisetal.2024,
  author    = {Windm{\"u}ller, Anna and Schaps, Kristian and Zantis, Frederik and Domgans, Anna and Taklu, Bereket Woldegbreal and Yang, Tingting and Tsai, Chih-Long and Schierholz, Roland and Yu, Shicheng and Kungl, Hans and Tempel, Hermann and Dunin-Borkowski, Rafal E. and H{\"u}ning, Felix and Hwang, Bing Joe and Eichel, R{\"u}diger-A.},
  title     = {Electrochemical activation of LiGaO2: implications for ga-doped garnet solid electrolytes in li-metal batteries},
  series = {ACS Applied Materials \& Interfaces},
  volume    = {16},
  journal   = {ACS Applied Materials \& Interfaces},
  number    = {30},
  publisher = {ACS Publications},
  address   = {Washington, DC},
  issn      = {39181-3919},
  doi       = {10.1021/acsami.4c03729},
  pages     = {14 Seiten},
  year      = {2024},
  abstract  = {Ga-doped Li7La3Zr2O12 garnet solid electrolytes exhibit the highest Li-ion conductivities among the oxide-type garnet-structured solid electrolytes, but instabilities toward Li metal hamper their practical application. The instabilities have been assigned to direct chemical reactions between LiGaO2 coexisting phases and Li metal by several groups previously. Yet, the understanding of the role of LiGaO2 in the electrochemical cell and its electrochemical properties is still lacking. Here, we are investigating the electrochemical properties of LiGaO2 through electrochemical tests in galvanostatic cells versus Li metal and complementary ex situ studies via confocal Raman microscopy, quantitative phase analysis based on powder X-ray diffraction, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and electron energy loss spectroscopy. The results demonstrate considerable and surprising electrochemical activity, with high reversibility. A three-stage reaction mechanism is derived, including reversible electrochemical reactions that lead to the formation of highly electronically conducting products. The results have considerable implications for the use of Ga-doped Li7La3Zr2O12 electrolytes in all-solid-state Li-metal battery applications and raise the need for advanced materials engineering to realize Ga-doped Li7La3Zr2O12for practical use.},
  language  = {en}
}
@inproceedings{WittigRuettersBragard2024,
  author    = {Wittig, M. and R{\"u}tters, Ren{\´e} and Bragard, Michael},
  title     = {Application of RL in control systems using the example of a rotatory inverted pendulum},
  series = {Tagungsband AALE 2024 : Fit f{\"u}r die Zukunft: praktische L{\"o}sungen f{\"u}r die industrielle Automation},
  booktitle = {Tagungsband AALE 2024 : Fit f{\"u}r die Zukunft: praktische L{\"o}sungen f{\"u}r die industrielle Automation},
  editor    = {Reiff-Stephan, J{\"o}rg and J{\"a}kel, Jens and Schwarz, Andr{\´e}},
  publisher = {le-tex publishing services GmbH},
  address   = {Leipzig},
  isbn      = {978-3-910103-02-3},
  doi       = {10.33968/2024.53},
  pages     = {241 -- 248},
  year      = {2024},
  abstract  = {In this paper, the use of reinforcement learning (RL) in control systems is investigated using a rotatory inverted pendulum as an example. The control behavior of an RL controller is compared to that of traditional LQR and MPC controllers. This is done by evaluating their behavior under optimal conditions, their disturbance behavior, their robustness and their development process. All the investigated controllers are developed using MATLAB and the Simulink simulation environment and later deployed to a real pendulum model powered by a Raspberry Pi. The RL algorithm used is Proximal Policy Optimization (PPO). The LQR controller exhibits an easy development process, an average to good control behavior and average to good robustness. A linear MPC controller could show excellent results under optimal operating conditions. However, when subjected to disturbances or deviations from the equilibrium point, it showed poor performance and sometimes instable behavior. Employing a nonlinear MPC Controller in real time was not possible due to the high computational effort involved. The RL controller exhibits by far the most versatile and robust control behavior. When operated in the simulation environment, it achieved a high control accuracy. When employed in the real system, however, it only shows average accuracy and a significantly greater performance loss compared to the simulation than the traditional controllers. With MATLAB, it is not yet possible to directly post-train the RL controller on the Raspberry Pi, which is an obstacle to the practical application of RL in a prototyping or teaching setting. Nevertheless, RL in general proves to be a flexible and powerful control method, which is well suited for complex or nonlinear systems where traditional controllers struggle.},
  language  = {en}
}
@article{YoshinobuMiyamotoWagneretal.2024,
  author    = {Yoshinobu, Tatsuo and Miyamoto, Ko-ichiro and Wagner, Torsten and Sch{\"o}ning, Michael Josef},
  title     = {Field-effect sensors combined with the scanned light pulse technique: from artificial olfactory images to chemical imaging technologies},
  series = {Chemosensors},
  volume    = {12},
  journal   = {Chemosensors},
  number    = {2},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {2227-9040},
  doi       = {10.3390/chemosensors12020020},
  pages     = {Artikel 20},
  year      = {2024},
  abstract  = {The artificial olfactory image was proposed by Lundstr{\"o}m et al. in 1991 as a new strategy for an electronic nose system which generated a two-dimensional mapping to be interpreted as a fingerprint of the detected gas species. The potential distribution generated by the catalytic metals integrated into a semiconductor field-effect structure was read as a photocurrent signal generated by scanning light pulses. The impact of the proposed technology spread beyond gas sensing, inspiring the development of various imaging modalities based on the light addressing of field-effect structures to obtain spatial maps of pH distribution, ions, molecules, and impedance, and these modalities have been applied in both biological and non-biological systems. These light-addressing technologies have been further developed to realize the position control of a faradaic current on the electrode surface for localized electrochemical reactions and amperometric measurements, as well as the actuation of liquids in microfluidic devices.},
  language  = {en}
}
@article{ZhantlessovaSavitskayaKistaubayevaetal.2024,
  author    = {Zhantlessova, Sirina and Savitskaya, Irina and Kistaubayeva, Aida and Ignatova, Ludmila and Talipova, Aizhan and Pogrebnjak, Alexander and Digel, Ilya},
  title     = {Correction: Zhantlessova et al. advanced "Green" prebiotic composite of bacterial cellulose/pullulan based on synthetic biology-powered microbial coculture strategy. Polymers 2022, 14, 3224},
  series = {Polymers},
  volume    = {16},
  journal   = {Polymers},
  number    = {13},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {2073-4360},
  doi       = {10.3390/polym16131802},
  pages     = {2 Seiten},
  year      = {2024},
  language  = {en}
}
@article{ZhenLiangStaatetal.2024,
  author    = {Zhen, Manghao and Liang, Yunpei and Staat, Manfred and Li, Quanqui and Li, Jianbo},
  title     = {Discontinuous fracture behaviors and constitutive model of sandstone specimens containing non-parallel prefabricated fissures under uniaxial compression},
  series = {Theoretical and Applied Fracture Mechanics},
  volume    = {131},
  journal   = {Theoretical and Applied Fracture Mechanics},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0167-8442},
  doi       = {10.1016/j.tafmec.2024.104373},
  pages     = {Artikel 104373},
  year      = {2024},
  abstract  = {The deformation and damage laws of non-homogeneous irregular structural planes in rocks are the basis for studying the stability of rock engineering. To investigate the damage characteristics of rock containing non-parallel fissures, uniaxial compression tests and numerical simulations were conducted on sandstone specimens containing three non-parallel fissures inclined at 0°, 45° and 90° in this study. The characteristics of crack initiation and crack evolution of fissures with different inclinations were analyzed. A constitutive model for the discontinuous fractures of fissured sandstone was proposed. The results show that the fracture behaviors of fissured sandstone specimens are discontinuous. The stress-strain curves are non-smooth and can be divided into nonlinear crack closure stage, linear elastic stage, plastic stage and brittle failure stage, of which the plastic stage contains discontinuous stress drops. During the uniaxial compression test, the middle or ends of 0° fissures were the first to crack compared to 45° and 90° fissures. The end with small distance between 0° and 45° fissures cracked first, and the end with large distance cracked later. After the final failure, 0° fissures in all specimens were fractured, while 45° and 90° fissures were not necessarily fractured. Numerical simulation results show that the concentration of compressive stress at the tips of 0°, 45° and 90° fissures, as well as the concentration of tensile stress on both sides, decreased with the increase of the inclination angle. A constitutive model for the discontinuous fractures of fissured sandstone specimens was derived by combining the logistic model and damage mechanic theory. This model can well describe the discontinuous drops of stress and agrees well with the whole processes of the stress-strain curves of the fissured sandstone specimens.},
  language  = {en}
}