Article
Materials Science, Composites
M. C. C. B. Gomes, L. D. R. Cardoso, D. D. Damm, F. S. Da Silva, E. J. Corat, V. J. Trava-Airoldi
Summary: The study focused on enhancing the interlaminar properties of composites by depositing carbon nanotubes on carbon fiber surfaces. The results showed improved adhesion between carbon fibers and the matrix, leading to increased shear strength and fracture toughness. However, limitations were observed in the fracture toughness analysis due to fragile pathways in intralaminar regions.
COMPOSITE INTERFACES
(2021)
Article
Construction & Building Technology
Tingwei Shi, Xihong Zhang, Hong Hao, Guanyu Xie
Summary: In this study, the shear performance of a new type of interlocking brick is systematically investigated. Laboratory shear tests and numerical models are used to study the shear capacity and influences of different factors on the shear response of interlocking prisms. An empirical design formula is proposed based on the results to predict the shear capacity of the interlocking brick.
JOURNAL OF BUILDING ENGINEERING
(2021)
Article
Materials Science, Ceramics
Jiming Zhou, Kangdi Zhong, Chentong Zhao, Haiming Meng, Lehua Qi
Summary: The study focused on enhancing magnesium alloy composites by grafting different amounts of carbon nanotubes onto carbon fiber surfaces. Moderate interlaminar shear strength was found to be beneficial for improving tensile properties, with the presence of carbon nanotubes delaying crack propagation and increasing energy consumption to enhance strength. Adjusting the quantities of grafted carbon nanotubes optimized crack propagation paths and affected stress distribution, crack initiation, and propagation.
CERAMICS INTERNATIONAL
(2021)
Article
Construction & Building Technology
Sonam Dorji, Hossein Derakhshan, David P. Thambiratnam, Tatheer Zahra, Alireza Mohyeddin
Summary: This paper presents a comprehensive experimental study on the behavior and basic material properties of semi-interlocking mortarless masonry. The experiments included testing of ungrouted masonry units, prisms, and wallets, as well as grouted cores. The results provide valuable information for understanding the behavior of semi-interlocking mortarless masonry and for developing material models for future research.
MATERIALS AND STRUCTURES
(2023)
Article
Engineering, Geological
Eiichi Ishii
Summary: The transmissivity of a fracture in fault zones can be influenced by various factors such as fracture roughness, initial aperture, effective normal stress, and tensile strength of the intact rock. Studies have shown that transmissivities decrease uniformly with increasing effective mean stress, although they can increase by shear-induced dilation. Understanding these interactions is vital for predicting flow behavior in fault zone fractures.
ENGINEERING GEOLOGY
(2021)
Article
Construction & Building Technology
B. V. Venkatarama Reddy, R. Sri Bhanupratap Rathod
Summary: The paper investigates the performance of steel studs embedded cement stabilised rammed earth (CSRE) in terms of compression, shear, and flexure. The results show that the introduction of shear studs significantly improves the shear and flexural strength of CSRE, and helps prevent catastrophic failures.
JOURNAL OF BUILDING ENGINEERING
(2022)
Article
Mathematics, Interdisciplinary Applications
Shuang Yi, Sheng Zheng, Shanshan Yang, Guangrong Zhou
Summary: This paper uses the capillary bundle model to study the flow in porous media and proposes a quantitative model based on fractal geometry to analyze the relationship between hydraulic roughness of capillaries and micro-flow properties. The results show that rough surfaces increase the tortuosity of flow while decreasing the permeability.
FRACTALS-COMPLEX GEOMETRY PATTERNS AND SCALING IN NATURE AND SOCIETY
(2022)
Article
Materials Science, Multidisciplinary
Nina Graupner, Jorg Muessig
Summary: The study found that different test methods led to varying trends in ILSS depending on the fiber mass fraction and fiber fineness. IFSS decreased with higher fiber mass fractions and diameters, while ILSS showed different trends with different test methods. The influence of fiber fineness on ILSS was not statistically proven.
FRONTIERS IN MATERIALS
(2022)
Article
Chemistry, Physical
Jian Wang, Tianqi Qiao, Aidong Wang, Xiudong Li, Tao Wang
Summary: A method of constructing high strength and toughness at the interface of Al/CFRP/Al laminate is proposed by adding resin and carbon nanotubes. Experimental results show that gullies and micropores on the surface of aluminum can increase the contact area between aluminum and matrix. Adding resin to the Al/CFRP interface improves the shear and bending strength as well as impact resistance. Mixing carbon nanotubes into the resin further enhances the mechanical properties. Carbon nanotubes between the CFRP layers strengthen and toughen the resin at the interface, increasing the bending strength and impact resistance by resisting resin damage and hindering crack propagation.
Article
Materials Science, Composites
Kadir Bilisik, Gulhan Erdogan, Nesrin Karaduman, Erdal Sapanci
Summary: Introducing nanostitching technology into 3D carbon/epoxy composites can improve shear and interlaminar shear properties while potentially decreasing tensile properties. Under different loading conditions, multi-nanostitched structures have different effects on the failure modes and paths of the composites.
APPLIED COMPOSITE MATERIALS
(2022)
Article
Chemistry, Physical
Jingchong Fan, Lili Wu, Bo Zhang
Summary: The study found that an increase in interface fractal dimension would improve the splitting tensile strength (f(ts)). The influence of interface roughness on the bonding property of new-to-old concrete is significant, while the effect of freeze-thaw cycles mainly occurs in the initial stage of deterioration.
Article
Engineering, Geological
Shibing Huang, Gang Liu, Fei Liu, Zekun Xin, Haowei Cai
Summary: Warming softening of ice-filled joints in cold regions has caused rockfall disasters. This study conducts a series of tests to investigate the thawing softening mechanism of ice-filled joints, considering the effects of joint opening, temperature, and roughness. The results show that temperature is a significant factor impacting the tensile strength of the joints, while joint opening has little influence. The shear strength decreases with increasing infill thickness, and when the temperature reaches -0.5 degrees C, shear failure is mainly caused by debonding of the ice-rock interface. A new shear strength model is proposed based on the experimental results, which accurately predicts the shear strength of ice-filled joints and can be used for stability estimation in freezing joint rock slopes in cold regions.
ENGINEERING GEOLOGY
(2023)
Article
Materials Science, Multidisciplinary
Yufeng Bi, Min Sun, Shuo Jing, Derui Hou, Wei Zhuang, Sai Chen, Xuwang Jiao, Quanman Zhao
Summary: This study analyzed the interlaminar shear characteristics of a polyurethane mixture composite structure and quantitatively calculated its energy consumption and carbon emissions. The results showed that using appropriate interlayer treatment schemes can improve interlaminar shear strength in different structures. Additionally, compared to Stone Matrix asphalt, the PU mixture exhibited lower energy consumption and carbon emissions, making it an environmentally friendly road pavement material.
Article
Materials Science, Multidisciplinary
Lixia Zhang, Hui Pan, Zhan Sun, Jiawei Ma, Qing Chang, Bo Zhang
Summary: p-type skutterudite (p-SKD) with laser patterned CoMo barrier layers were fabricated by a one-step hot press sintering process. Then the p-SKD coated by CoMo barriers layers with different patterned parameters were brazed with Cu electrodes. The shear strength increased by-1.5 times after laser processing.
Article
Materials Science, Composites
Jiangyuan Wu, Yahui Zhang, Yaohui Ji, Rongxian Zhu, Yuhui Sun, Yanglun Yu, Wenji Yu
Summary: The adhesive ability of bamboo scrimber is crucial for its application in large-scale engineering structures. Cold-pressed bamboo scrimber with different sanding mesh and density was bonded using polyurethane resin. The concentration of adhesive on the surface facilitated anchoring into the material. The study examined shear strength and immersion peel strength as parameters to evaluate glue quality. The optimal gluing characteristics were obtained with 120 grit sandpaper and a density of 1.15 g/cm(3).
POLYMER COMPOSITES
(2022)
Article
Engineering, Multidisciplinary
Stefan Thielen, Thirumanikandan Subramanian, Bernd Sauer, Oliver Koch, Richard Boerner, Thomas Junge, Andreas Schubert
Summary: A simplified micro scale hydrodynamic simulation model is presented to study the axial flow of lubricant induced by the shaft counter-surface (SCS) of a sealing system. The influence of machining parameters on the lubricant flow along the axial direction is investigated using the simulation model. The model is validated with experimental results.
FORSCHUNG IM INGENIEURWESEN-ENGINEERING RESEARCH
(2023)
Article
Materials Science, Coatings & Films
Maximilian Grimm, Susan Conze, Lutz-Michael Berger, Sven Thiele, Thomas Lindner, Thomas Lampke
Summary: Ternary compositions of the Al2O3-Cr2O3-TiO2 system were prepared as feedstock powders and used to prepare coatings. The experimental powders formed solid solutions of (Al,Cr)2O3 and (Al,Cr,Ti)2O3. The use of agglomeration and sintering improved the deposition efficiency and the addition of TiO2 allowed for tailoring of electrical resistance.
SURFACE & COATINGS TECHNOLOGY
(2023)
Article
Engineering, Mechanical
Wangping Wu, Yicheng Zhou, Guang He, Nather Johannes, Yaxuan Liu, Frank Koester, Thomas Lampke
Summary: Ni-Re alloy coatings were electrodeposited from Watts's type and citrate solutions, with Re-content ranging from 0 to 80 wt%. The microstructure, crystallographic texture, deposition rate, grain size, microhardness, and abrasion resistance of the coatings were investigated. The results revealed that high Re-content led to microcracking in the coatings, while low Re-content resulted in dense and homogeneous coatings. Increasing Re-content created fine nanocrystalline structures with smaller grain sizes. The deposition rate was higher in the citrate solution than in the Watts's solution. The microhardness increased with Re-content, and the wear coefficient decreased. A Ni-Re alloy coating with 80 wt% Re exhibited the best abrasion resistance, with the lowest wear coefficient of approximately 6.2 x 10(-16) m(3) m(-1) N-1.
Article
Chemistry, Physical
Sarah Johanna Hirsch, Patrick Eiselt, Ismail Ozdemir, Thomas Grund, Andreas Nestler, Thomas Lampke, Andreas Schubert
Summary: AlSi7Mg/SiCp aluminum matrix composites (AMCs) with a high ceramic content (35 vol.%) were evaluated as a potential substitute for grey cast iron brake discs. The prepared AMC samples were tested against conventional brake lining material in a pin-on-disc configuration to simulate automotive brake system conditions. The coefficient of friction remained constant when the set pressure was reached, while the initial surface topography of the samples varied significantly.
Article
Chemistry, Physical
Erik Saborowski, Philipp Steinert, Thomas Lindner, Andreas Schubert, Thomas Lampke
Summary: Laser structuring is extensively studied for metal surface-pretreatment to enhance adhesion in polymer-metal hybrids. Cone-like protrusions exhibit excellent wetting behavior and high compound strength but require significant processing time. This paper investigates a process strategy for creating scalable pin structures using single pulse drilling with an Nd/YVO4 nanosecond laser system on EN AW-6082 aluminum alloy. Experimental results show that pulse drilling can achieve pin structures with high aspect ratio and strength values comparable to cone-like protrusions, but with a much higher processing rate.
Article
Chemistry, Analytical
Susanne Quitzke, Igor Danilov, Andre Martin, Roy Morgenstern, Thomas Lampke, Andreas Schubert
Summary: Local anodization with a free electrolyte jet is a suitable solution for localized surface functionalization. This study used numerical calculations to understand the formation of the anodic oxide layer on aluminum alloy EN AW-7075. The simulation results showed a decreasing oxide layer thickness at increasing radial distance from the center of the jet, consistent with experimental results.
Article
Materials Science, Multidisciplinary
Lisa-Marie Rymer, Thomas Lindner, Thomas Lampke
Summary: By investigating HVOF coatings, it was found that adding Niobium and Molybdenum can significantly reduce wear depth at high temperatures, making high-entropy alloys (HEAs) a resource-saving and high-temperature wear-resistant coating material.
Article
Materials Science, Multidisciplinary
Thomas Lindner, Bianca Preuss, Martin Loebel, Lisa-Marie Rymer, Maximilian Grimm, Holger Schwarz, Thomas Seyller, Thomas Lampke
Summary: Compositional alterations to high-entropy alloys (HEAs) can be used to further develop their properties for coating technologies and surface-protection applications. In this study, minor quantities of the non-metallic alloying constituents BSiC were added to the CrFeNi base system. The wear resistance of the alloy was significantly increased compared to the BSiC-free variant. The evaluation of the process-structure-property relationships confirmed the great potential of developing load-adapted HEA systems using non-metallic alloy constituents in surface engineering.
Article
Materials Science, Multidisciplinary
Diego Delgado Arroyo, Tim Richter, Dirk Schroepfer, Andreas Boerner, Michael Rhode, Thomas Lindner, Bianca Preuss, Thomas Lampke
Summary: This study assessed the effect of different machining conditions on the machinability of Multi-Principal-Element or High-Entropy Alloys (MPEAs/HEAs). The results showed that using ultrasonic-assisted milling at low feed per cutting edge and low cutting speed can reduce cutting forces and process temperatures. It was demonstrated that both conventional and ultrasonic-assisted milling methods are viable for machining these modern alloys.
Article
Materials Science, Multidisciplinary
Bianca Preuss, Thomas Lindner, Thomas Uhlig, Jorge Eduardo Tapia Cabrera, Holger Schwarz, Guntram Wagner, Thomas Seyller, Thomas Lampke
Summary: The microstructural evolution of high-entropy alloys during different preparation processes was investigated. It was found that the lamellar structure in laser metal deposition (LMD) coatings showed vertical solidification due to the remelting of powder, while the lamellar orientation in spark plasma sintering (SPS) materials was determined by the microstructure of the powder. The LMD coatings exhibited improved functional properties compared to the SPS materials. The influence of lamellar orientation on tribological properties was reduced after heat treatment, and the influence of lamellar size on material properties could be derived.
Article
Materials Science, Multidisciplinary
Mehri Hashemzadeh, Frank Simchen, Lisa Winter, Thomas Lampke
Summary: Al2O3 coatings produced by PEO provide excellent corrosion and wear resistance, but their fracture toughness is limited due to the brittleness of the oxide ceramic. Incorporating ZrO2 into alumina to form ZTA can enhance the fracture tolerance. In this study, an Al2O3-ZrO2 composite coating was successfully applied on a 6082 aluminum alloy, and the incorporation of ZrO2 resulted in a thicker coating with improved passivation and higher fracture toughness.
Article
Materials Science, Multidisciplinary
Roy Morgenstern, Claudia Albero Rojas, Frank Simchen, Vanessa Meinhold, Thomas Mehner, Thomas Lampke
Summary: Potentiodynamic and potentiostatic polarization tests were conducted in aluminate-phosphate electrolytes to investigate the layer formation on a high-strength, dual-phase steel substrate. The results showed that iron hydroxides or oxides were initially formed at low potentials regardless of the electrolyte composition. At around 1 V vs. standard hydrogen electrode (SHE), the current density increased significantly and led to the formation of porous layers. The composition of the layer varied with the addition of phosphate to the electrolyte, with the highest phosphate content leading to pronounced crack networks.
Article
Materials Science, Multidisciplinary
Maximilian Grimm, Pia Kutschmann, Christian Pluta, Olga Schwabe, Thomas Lindner, Thomas Lampke
Summary: This study investigates the suitability of polarization measurements for non-destructive quality testing of thermally sprayed coatings. A gel electrolyte and a three-electrode system were developed to prevent corrosion and enable accurate evaluation of coating microstructure. The new method was found to detect even slight differences in oxide content within coatings and offers a promising opportunity to evaluate coating quality in a non-destructive manner.
