Modal stress analysis of a cracked woven composite beam under compression

6th International Conference on Material Science and Engineering Technology, ICMSET 2017 -- 20 October 2017 through 22 October 2017 -- -- 212519In this study, modal stress analysis of carbon fiber plain weave cracked composite beams under compression is considered. General-purpose finite element code MSC. Marc is used for the finite element beam models. Before understanding the compression effect on the beam, dynamic characteristics of the models are compared with the experimental evaluations. Investigation of quasi-static and dynamic (equivalent von Mises stress and elastic strain energy density) behavior of the plain weave cracked beams with two different thicknesses under compression is examined numerically. Results are given in tabular and graphical form. © 2018 Trans Tech Publications, Switzerland.Firat University Scientific Research Projects Management Unit 2014-77654622-01 British Association for PsychopharmacologyThis work was supported by the Scientific Research Projects Unit (BAP) of Bulent Ecevit University (project code no: 2014-77654622-01)

Finite element analysis

In this chapter, essentials of finite element analysis on musculoskeletal biomechanics are studied. For this reason, some fundamental types of finite elements, methodology, and difficulties of finite element analysis are considered. Also, some information on well-known general purpose finite element codes preferred in biomechanics and biomaterials world is given. Before discussing orthopedic researches for clinical relevance, an example of two-dimensional finite element analysis is examined. © Springer International Publishing Switzerland 2016

Experimental dynamic analysis on naturally curved honeycomb sandwich beams with different damage patterns

In this study, dynamic analysis of naturally curved honeycomb sandwich beam including two surface cracks and an impact region at the facing skin is presented. Laminates of facing skin and backing skin are known as carbon fiber-plain weave composite laminates with 1.6 mm in thickness. In the first part, in order to determine mechanical properties of both the skin with no-crack/crack(s) and the honeycomb core of the composite beam, static tensile tests are conducted with respect to straingage measurement technique. In the second part, drop weight impact tests and vibration tests are performed to present the free vibration characteristics of the clamped-clamped honeycomb sandwich beam including cracks and an impact-damaged region. Corresponding to damage patterns of the sandwich beam, experimental dynamic analyses consist of six steps: (1) Vibration analysis with no-crack and no-impact region, (2) Vibration analysis with no-crack and an impact region, (3) Vibration analysis with a surface crack and no-impact region, (4) Vibration analysis with a surface crack and an impact region, (5) Vibration analysis with two surface cracks and no-impact region, (6) Vibration analysis with two surface cracks and an impact region. For these purposes, an impact hammer with a force transducer is used to excite the undamaged or damaged naturally curved honeycomb sandwich beam through the selected points. After the excitation, the responses are obtained by an accelerometer. Resonant frequencies for the modal responses of the naturally curved honeycomb sandwich beam with different damage patterns are discussed. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Dynamic analysis of bovine hydroxyapatite/CaTiO3 bioceramics

In this study, modal analysis and vibro-acoustic investigation are considered to determine dynamic characteristics of bovine hydroxyapatite/calcium titanate bioceramics. Results show that first natural frequencies increase with increasing sintering temperature for all groups. The addition of calcium titanate to bovine hydroxyapatite causes the natural frequency to ascend. Similarly, damping ratios for all groups go up with increasing sintering temperature and calcium titanate addition to bovine hydroxyapatite raises damping ratios for vibration. The addition of calcium titanate to bovine hydroxyapatite significantly raises sound damping capability and damping slightly increases with raising sintering temperature. © 2018 by the authors

Finite strip with a central crack under tension

In this study, a symmetrical finite strip with a length of 2L and a width of 2h, containing a transverse symmetrical crack of width 2a at the midplane is considered. Two rigid plates are bonded to the ends of the strip through which uniformly distributed axial tensile load of magnitude 2hp(0) is applied. The material of the strip is assumed to be linearly elastic and isotropic. Both edges of the strip are free of stresses. Solution for this finite strip problem is obtained by means of an infinite strip of width 2h which contains a crack of width 2a at y = 0 and two rigid inclusions of width 2c at y = L and which is subjected to uniformly distributed axial tensile load of magnitude 2hp(0) at y = +/-infinity. When the width of the rigid inclusions approach the width of the strip, i.e., when c -> h, the portion of the infinite strip between the inclusions becomes identical with the finite strip problem. Fourier transform technique is used to solve the governing equations which are reduced to a system of three singular integral equations. By using the Gauss-Jacobi and the Gauss-Lobatto integration formulas, these integral equations are converted to a system of linear algebraic equations which is solved numerically. Normal and shearing stress distributions and the stress intensity factors at the edges of the crack and at the corners of the finite strip are calculated. Results are presented in graphical and tabular forms

An experimental investigation of damaged plain-weave reinforced laminates using modal analysis

7th Australasian Congress on Applied Mechanics, ACAM 2012 -- 9 December 2012 through 12 December 2012 -- Adelaide, SA -- 107563In this study, dynamic analysis of carbon fiber plate including two surface cracks and a holenotch is considered. Six carbon fiber-plain weave composite plates are provided by TAI-Turkish Aerospace Industry Inc., Turkey. Each of the six plates is 100 × 100 mm square and three of them are four-ply laminate (2.798 mm in thickness) and the last three are five-ply laminate (3.06 mm in thickness). Also, in order to compare the mechanical properties of carbon fiber-plain weave composite plates, static tensile tests are conducted. Then, vibration tests are performed to present the free vibration characteristics of clamped-free carbon fiber-plain weave composite plates. In addition to that, the prediction of resonant frequencies for the modal responses of four-and five-ply laminated carbon composite plates is studied. Corresponding to damage patterns, these experimental dynamic analyses consist of four parts: (1) Vibration analysis with no-damage, (2) Vibration analysis with holenotch, (3) Vibration analysis with a hole-notch and a surface crack damages, (4) Vibration analysis with a hole-notch and two surface crack damages. For these purposes, an impact hammer with a force transducer is used to excite the undamaged or damaged plain weave composite plate through the selected points. After the excitation, the responses are obtained by an accelerometer. The vibration measurements are completed using a microprocessor-based data acquisition system

Studies on goat hydroxyapatite/commercial inert glass biocomposites

In this study, mechanical properties and microstructural analysis of goat-derived hydroxyapatite/commercial inert glass biocomposites are considered in the temperature range between 1000 and 1300 °C. The results indicate that the best values of maximum compressive strength and microhardness are achieved in the samples sintered at 1200 °C for the glass in the weight of 5 and 10%. Moreover, above 1000 °C, decomposition of hydroxyapatite and new phase formations such as whitlockite and silicocarnotite play also a major role in the hardness and strength for goat hydroxyapatite/commercial inert glass biocomposites. © 2018, Australian Ceramic Society