The Flexural Fatigue Behavior of Honeycomb Sandwich Composites Following Low Velocity Impacts

This study experimentally investigated the flexural fatigue behaviors of honeycomb sandwich composites subjected to low velocity impact damage by considering the type and thickness of the face sheet material, the cell size and the core height parameters. Carbon-fiber reinforced composite and the aluminum alloy was used as the face sheet material. First, the static strength of undamaged and damaged specimens was determined by three-point bending loads. Secondly, the fatigue behaviors of the damaged and undamaged specimens were determined. Low velocity impact damage decreased the flexural strength and fatigue lives but increased the damping ratio for all specimens. Maximum damping ratio values were observed on specimens with a aluminum face sheet

Yapıştırıcı ve Perçinle Birleştirilmiş Çift Bindirme Bağlantılarında ilerlemeli Hasar Analizi

Konferans Bildirisi -- Teorik ve Uygulamalı Mekanik Türk Milli Komitesi, 2011Conference Paper -- Theoretical and Applied Mechanical Turkish National Committee, 2011Bu çalışmada, yapıştırıcı ve perçin kullanılarak birleştirilmiş çift bindirme bağlantılarında ilerlemeli hasar analizi gerçekleştirilmiştir. Bağlantılarda ana malzeme olarak örgü tipi cam fiber takviyeli kompozit malzeme kullanılmıştır. Analizler APDL (Parametric Design Language) kodlan kullanılarak yazılan bir program yardımı ile Ah/SYS 12.1 sonlu elamanlar paket programı kullanılarak gerçekleştirilmiştir. 30, 45 ve 60 mm olmak üzere üç farklı bindirme mesafesi için yapıştırıcı ve perçin kullanılarak birleştirilmiş bağlantıların ilerlemeli hasar analizi sonucunda elde edilen hasar yükleri ve hasar tipleri Maksimum Kayma Gerilmesi Teorisi ve Hashin Kriterine göre tespit edilmiştir. Elde edilen sonuçlar birleştirme tipine ve bindirme mesafesine göre karşılaştırılarak sunulmuştur

NUMERICAL ANALYSIS OF THE EFFECT OF IMPLANT GEOMETRY TO STRESS DISTRIBUTIONS OF DENTAL IMPLANT SYSTEM

ABSTRACT Purpose: The success of dental implants is related to the quality, quantity of local bones, implant design and surgical technique. Implant diameter and length are accepted as key factors. Present work focuses to investigate the effect of titanium implant geometry to stress distributions in implant system.Materials and Methods: For this purpose three different implant models which are currently being used in clinical cases constructed by using ANSYS Workbench 12.1. The stress distributions on components of implant system  under static loadings were analyzed for all models.Results: The maximum stress values that occurred in all components happen in the case of loading in which the Nucleoss T-4 implant is used, but the occurred lowest stress values happen in the case of Fı loading in which Nobel Active  implant is used. In all models, the maximum tensions have occurred in the neck region of the implants.Conclusion: The crested loss of bones in the neck region of the implants lessen the long-term survival rate of implants.The lengt and the size of the implant are the two important factors in the stress distribution

A new hydrazone compound with ester groups: synthesis, spectroscopic studies, crystal structure, and electrochemical supercapacitor applications

We work and report the synthesis, spectroscopic results, and crystal structure of the title compound (H2L1), in this manuscript. The crystal structure of the title compound was determined using the X-ray diffraction method. This compound crystallized in the monoclinic system, space group P21/c. There is a trans configuration in the molecule, formed according to the C = N bond. The N–H…O, O–H…N hydrogen bond interactions and a weak C–H…π interactions stabilize the molecules in the lattice. The supercapacitive performance of H2L1-modified GCPE electrodes was tested for the first time and resulted in 192.65 F g−1 supercapacitance and 26.76 Wh kg−1 specific energy values at a scan rate of 20 mV s−1. It is anticipated that H2L1 contributes the electrochemical performance and will be a very promising material for energy storage applications

Characterization of Hazelnut, Pistachio, and Apricot Kernel Shell Particles and Analysis of Their Composite Properties

In this study, hazelnut, pistachio, and apricot kernel shells were ground size of 0–300 µm, 300–600 µm, and 600–850 µm. The cellulose, ash, humidity, and metal contents of these powder particles were chemically analyzed and structural properties were characterized using X-Ray Diffraction (XRD) and Fourier Transform Infrared Spectrometer (FT-IR) analysis. Their composites were fabricated by adding 0%, 10%, 20%, and 30% by weight of these powder particles to the polyester matrix material. The effect of chemical and structural properties of the powder particles on the physical, thermal, and mechanical properties of the composites was analyzed. The XRD analysis revealed that cellulose structure observed in powder particles. The peaks observed in their surface functional structures with FT-IR were mainly caused by cellulose and hemicellulose structures. These structures effected humidity and ash ratios. Nitrogen, carbon, hydrogen, and oxygen elements were seen in the structure. In addition, heavy metals such as Sn, Ca, K, Na, Mg, Fe, Ni, Mn, Cu, Zn, and Si were found. Powder particles added to the polyester material adversely affected the tensile strength of the matrix material. However, powder particles added to the matrix material at low rates had a positive effect on bending and compressive strength