Materials Testing-Materials and Components Technology and Application最新文献

{"title":"Specific crack enthalpy as material characterization parameter","authors":"M. Es-Saheb, S. Khan","doi":"10.3139/120.111158","DOIUrl":"https://doi.org/10.3139/120.111158","url":null,"abstract":"Abstract In this study, the specific crack enthalpy (damage), considered a material characterization parameter according to crack layer theory, is discussed. The crack region and its accompanying damage become a crack layer. Fatigue crack propagation experiments were conducted on HT60 and HT80 steel. The specific enthalpy γ* of fracture due to ductile crack propagation in steel HT60 and HT80 has been calculated. The energy release rate and damage coefficients were determined at different stress ratios varying from R = 0.04 to 0.8. The crack layer translational resistance moment R1 has been determined. Because interpreting the data of crack propagation on two types of steel in the light of this theory reveals reasonable similarity, the need to set up experiments specifying the limitations and applicability of the theory is essential.","PeriodicalId":351153,"journal":{"name":"Materials Testing-Materials and Components Technology and Application","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124949186","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of preload moment on the strength of mechanically fastened joints in woven glass-epoxy prepregs","authors":"Ümran Esendemir,, Ayşe Öndürücü","doi":"10.3139/120.111168","DOIUrl":"https://doi.org/10.3139/120.111168","url":null,"abstract":"Abstract This study presents the effects of geometric parameters of mechanically fastened joints on their ultimate bearing strength, net ultimate tensile strength and ultimate shear strength under various preloads. In the experiments, two different geometric parameters were considered: edge distance-to-hole diameter ratio (E/D) and plate width-to-hole diameter ratio (W/D), and magnitudes of preload moments applied on the specimens at about 0, 2, 4 and 6 Nm. Damage to the specimens subjected to different moments of the same geometric dimensions was examined by using a scanning electron microscope (SEM). The experimental test results showed that the ultimate bearing strengths, net ultimate tensile strengths and ultimate shear strengths are strictly affected by the geometrical parameters and the magnitude of the preload moment.","PeriodicalId":351153,"journal":{"name":"Materials Testing-Materials and Components Technology and Application","volume":"65 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129238711","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hysteretic behavior of traditional Chinese timber frames under cyclic lateral loads","authors":"Q. Niu, Jia Wan, Tieying Li, Y. Chen","doi":"10.3139/120.111160","DOIUrl":"https://doi.org/10.3139/120.111160","url":null,"abstract":"Abstract The beam-column-bracket frame is a relatively complete system of most Pre-1386 (Ming Dynasty) Chinese timber structures, which transfers shear, compression, and bending from bracket to beam-column frame and then to the building base. Its structure is rather complex and there has been little information describing the force resistance behavior of these kinds of wood assemblies. In this paper, a single-layer half-scale 3D specimen with bucket arches and beam-column frame was tested under cyclic lateral loads achieved through a uniquely developed loading mechanism. The frame behavior was investigated under three different levels of gravity loads. The study results show that the beam-column joint serves as a weak link in the frame and the structure can return to the initial (or close to) equilibrium position during the unloading process as the columns exhibit the rocking mechanism. The wooden structure manifests good ductility despite its low energy dissipation capability. The variations of bearing c...","PeriodicalId":351153,"journal":{"name":"Materials Testing-Materials and Components Technology and Application","volume":"74 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115634234","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimization of germanium enrichment from waste optical fibers: A validation experiment using a hybrid approach","authors":"Soo-Young Lee, Min-Seok Lee, Sungkyu Lee, Sungsu Cho, Minhye Seo","doi":"10.3139/120.111167","DOIUrl":"https://doi.org/10.3139/120.111167","url":null,"abstract":"Abstract A batch-type and lab-scale germanium recovery method was developed via a hybrid approach combining pyro– and hydrometallurgical reactions to prove the feasibility of mass production and economic recovery of germanium from waste optical fibers. More specifically, the extent of pyro-metallurgical separation reaction was carefully examined to determine by trial and error its completion time which was 2 h at 700 °C. The post pyro-metallurgical reaction product was leached at 50, 65, and 80 °C for a maximum 8 hr retention at each temperature, using an optimized composition of aqueous HCl solution: maximum germanium recovery of 26 ppm was thus experimentally substantiated by using the ICP-OES method. XRF analysis was performed on the post-hydrometallurgical leaching residue to detect any significant composition of remaining Ge: The confirmation of Si, Cl, and Na as sole residual elements thus cogently substantiated the complete separation of germanium in accordance with the present hybrid approach. The...","PeriodicalId":351153,"journal":{"name":"Materials Testing-Materials and Components Technology and Application","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132967512","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Effects of Welding Speed on Microstructure and Mechanical Properties of Dissimilar Welded Joints by CO2 Laser Welding","authors":"M. Taşkin","doi":"10.3139/120.110528","DOIUrl":"https://doi.org/10.3139/120.110528","url":null,"abstract":"Abstract This study investigated the effects of welding speed on microstructure and mechanical properties of dissimilar welded joints (AISI 430 ferritic stainless steel and AISI 1010 low-carbon steel) by using CO2 laser beam welding. Laser beam welding (LBW) experiments were carried out under argon and helium shielding gas atmosphere at 2500 W constant heat input and 100–200–300 cm/min welding speeds. The microstructures of the welded joints were examined by optical microscopy, SEM, EDS, and X-ray analysis. The tensile strength of the welded joints was measured. The results of this study demonstrated that the best properties were observed at the specimens welded at a welding speed of 100 cm/min.","PeriodicalId":351153,"journal":{"name":"Materials Testing-Materials and Components Technology and Application","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125569960","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimierung der mechanischen und tribologischen Eigenschaften keramischer Schichten für die Knie‐Gelenkendoprothetik","authors":"J. Rahm, W. Glien, E. Kieselstein, K. Kreyßig, P. Sommer, E. Auerswald, U. Kremling","doi":"10.1002/9783527609017.CH141","DOIUrl":"https://doi.org/10.1002/9783527609017.CH141","url":null,"abstract":"","PeriodicalId":351153,"journal":{"name":"Materials Testing-Materials and Components Technology and Application","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123517663","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prof. Dr.-Ing. habil. Gerhard Pusch: 65 Jahre","authors":"H. Blumenauer, H. Spies","doi":"10.3139/120.050101","DOIUrl":"https://doi.org/10.3139/120.050101","url":null,"abstract":"","PeriodicalId":351153,"journal":{"name":"Materials Testing-Materials and Components Technology and Application","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124700506","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Induktions-Lockin-Thermografie : ein neues Verfahren zur zerstörungsfreien Prüfung","authors":"G. Riegert","doi":"10.18419/OPUS-1734","DOIUrl":"https://doi.org/10.18419/OPUS-1734","url":null,"abstract":"Die Qualitatssicherung von Bauteilen erfordert eine zuverlassige Defekterkennung (z.B. bei Inspektions- und Wartungsarbeiten), die jedoch durch die Anzeige intakter Bauteilstrukturen erschwert wird. Wenn selektiv nur Defekte auf die Anregung ansprechen, werden intakte Strukturen unterdruckt und somit die Wahrscheinlichkeit zur Defekterkennung (\"Probability of Defect Detection\" POD) erhoht. \u0000Die 1995 am IKP-ZfP entwickelte ultraschallangeregte Lockin-Thermografie (ULT) ist ein solches Verfahren, dessen Nachteil allerdings eine nicht kontaktfreie Anregung ist. Eine kontaktfreie und dennoch defektselektive Anregung ist die induktive Erwarmung durch Wirbelstrome (Ohmsche Verluste). Die Wirbelstrome erwarmen Defektstellen innerhalb der Wirbelstromeindringtiefe lokal starker als ungeschadigte Bauteilbereiche. \u0000 \u0000Stand der bisherigen Technik ist die Transienten-Thermografie mit pulsartiger Induktionsanregung. Bei ihr wird zur Auswertung das Bild des starksten Kontrasts aus der aufgenommenen Abkuhlungssequenz untersucht. Impulsangeregte Transienten-Thermografie hat den Vorteil einer kurzen Messzeit, allerdings sind die Ergebnisbilder durch inhomogene Erwarmung, wie sie bei induktiver Erwarmung haufig auftritt, und lokale Variation des Emissionskoeffizienten stark beeinflusst. \u0000 \u0000Durch Anwendung der Lockin-Thermografie Methode auf die induktive Erwarmung werden die Nachteile der Transienten-Thermografie uberwunden (\"Induktions-Lockin-Thermografie\" ILT). Im Gegensatz zur Transienten-Thermografie werden bei ILT die Wirbelstromamplituden (Frequenz von 30 bis 300 kHz) sinusformig moduliert (zwischen 0,01 und 1 Hz), ahnlich der Amplitude bei ultraschallangeregter Lockin-Thermografie, wahrend eine Infrarotkamera eine Infrarotbildsequenz uber mehrere Anregungsperioden aufnimmt. Eine pixelweise Fouriertransformation der Sequenz berechnet dann ein Amplituden- und ein Phasenbild. \u0000 \u0000Die Vorteile - speziell der Phasenbilder - sind dieselben wie bei den anderen Lockin-Thermografie Methoden: im Vergleich zu einzelnen Infrarotbildern haben die ILT-Phasenbilder ein erheblich verbessertes Signal/Rausch-Verhaltnis, und Temperaturgradienten werden unterdruckt. Auserdem ist die Tiefenreichweite an metallischen Werkstoffen mit ILT (begrenzt durch die thermische Eindringtiefe) im Vergleich zur konventionellen Wirbelstromprufung, die durch den \"Skin Effekt\" begrenzt ist, deutlich gesteigert. \u0000 \u0000Am IKP-ZfP wurde im Rahmen eines DFG-Projekts eine ILT-Anlage konzipiert und aufgebaut. Sie wurde anschliesend an verschiedenen Materialien und Fehlerarten erprobt und optimiert. Nach der theoretischen Herleitung der ILT-Tiefenreichweite wurde der tatsachliche Einfluss elektrischer und thermischer Materialeigenschaften auf die Tiefenreichweite an Modellproben untersucht. Eine weitere experimentelle Fragestellung war die Auflosungsgrenze von ILT bei der Defekterkennung. Neben der Inspektion von Modellproben wurde ILT auch zur Prufung von Praxisbauteilen herangezogen. Die Palette der dete","PeriodicalId":351153,"journal":{"name":"Materials Testing-Materials and Components Technology and Application","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134307094","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}