The tensile fatigue behaviour of a tightly woven carbon/carbon composite was investigated as a function of stress level. Load-controlled fatigue tests were performed in tension-tension mode with a stress ratio, R, of 0.1 under ambient laboratory conditions. Results of composite behaviour are discussed in terms of the relationship of the stress/strain behaviour to the fatigue life of these composites as well as the effects of applied stress levels. It is shown that these composites exhibit good resistance to cyclic loading. No fatigue failures were obtained after 10(6) cycles when the maximum tensile load in the fatigue cycle is less than or equal to 80% of the static tensile strength. Evidence of textural changes related to fatigue was observed in the matrix region of these composites.


Simulation of equal channel angular pressing applied to produce structures with ultrafine-sized grains
Karpuz, Pinar; Şimşir, Caner; Gür, Cemil Hakan (Inderscience Publishers, 2009-01-01)
Severe plastic deformation methods are of great interest in industrial forming applications, as they give rise to significant refinement in microstructures and improvements in mechanical and physical properties. In the 'equal channel angular pressing (ECAP)', which is the most common method for production of ultrafine grained bulk samples, very high plastic strains are introduced into the bulk material without any change in cross section. In this study, the plastic deformation behaviour of the materials sub...
A new framework for simulation of heat treatments
Şimşir, Caner; Gür, Cemil Hakan (Inderscience Publishers, 2010-12-01)
In this study, a mathematical framework based on finite element method (FEM) capable of predicting temperature history, evolution of phases and internal stresses during thermal treatment of metals and alloys was developed. The model was integrated into the commercial FEA software MSC.Marc® by user subroutines. The accuracy of the model was verified by simulating the quenching of eccentrically drilled steel cylinders. Simulation results were justified via SEM observations and XRD residual stress measurements.
Investigation of as-quenched and tempered commercial steels by Magnetic Barkhausen Noise method
Gür, Cemil Hakan; Çam, İbrahim (Inderscience Publishers, 2006-01-01)
This study aims to characterise as-quenched and tempered steels by the Magnetic Barkhausen Noise method, and to contribute to optimisation of heat treatment processes. Identical austenitisation and quenching procedures were applied to SAE 1040 and SAE 4140 specimens to eliminate the effect of grain size. Samples were tempered at 200°C and 600°C for 2 hours. Microstructures were characterised by metallographic examinations and hardness measurements. Amplitude, position and frequency spectrum of signals were ...
A surface crack in a graded coating subjected to sliding frictional contact
Dağ, Serkan; GÜLER, MEHMET ALİ; Gulgec, Mufit (Elsevier BV, 2012-01-01)
This article presents an analytical method developed to conduct fracture analysis of functionally graded coatings that are under the effect of contact stresses. The geometric model considered comprises a functionally graded coating, which possesses a surface crack and is perfectly bonded to a homogeneous half-plane. A two-step solution procedure is put forward in which the contact and crack problems are treated separately. First, the graded coating is assumed to be in sliding frictional contact with a rigid...
Tensile behavior of post-installed chemical anchors embedded to low strength concrete
YILMAZ, SALİH; Özen, Muhammet Ali; YARDIM, YAVUZ (Elsevier BV, 2013-10-01)
In the scope of this paper, tensile capacities of post-installed chemical anchors embedded to 5.9 and 10.9 MPa concrete blocks are investigated. Pull-out tests are applied to 80 ductile steel bars (S420a). For the anchor diameters, 12, 16 and 20 mm are chosen. On the other hand, 10, 15 and 20 times the bar diameter are selected as free-edge distance and embedment depth for monotonic tensile loading tests. The results indicate that installation of anchors into low-strength concrete with sufficient embedment ...
Citation Formats
A. OZTURK and R. MOORE, “TENSILE FATIGUE BEHAVIOR OF TIGHTLY WOVEN CARBON CARBON COMPOSITES,” COMPOSITES, pp. 39–46, 1992, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/65673.