The failure strength for pin-loaded multi-directional fiber-glass reinforced epoxy laminate

In this study, failure characteristics of laminated composites loaded by means of a single fastener were investigated. The development and evaluation of joint capability for both failure mode and ultimate load are the major aims. Tests have been carried out on single pinned joints in multi-directional glass-fiber reinforced epoxy for a range of laminate configurations and specimen geometry. For [90/0](2s), and [+/-45](2s) laminates with single-hole joints the strengths have been measured; the effects of variables such as ply orientation, laminate edge and side distances were discussed in the light of the results. In addition, by using finite element code PDNLPIN, a static progressive failure analysis was performed. Comparisons were made between the test data and the results of the model. The effect of material nonlinearity on the prediction of the failure loads was studied. Good agreement was found between numerical predictions and the experimental data

The strength of pinned joints in laminated composites

An investigation was performed to study the response of pin-loaded laminated composites. Tensile tests were performed on E/ glass-epoxy composites for two different ply orientations such as [0/+/-45](s) and [90/+/-45](s). For each ply orientation, 20 different geometries were chosen. The major focus of the study was to characterize the failure mechanisms and to evaluate the effect of geometric dimensions on the bearing, shear-out and net-tension strengths of pinned joints. For this purpose, the specimens were tested to find first failure and final failure load. In addition, by using finite element code PDNLPIN, a static progressive failure analysis was performed. The effect of the material non-linearity was taken into account on the mathematical forms. Comparisons were made between the test data and the results of the model and these showed good agreements. (C) 2003 Elsevier Science Ltd. All rights reserved

The effect of ply number, orientation angle and bonding type on residual stresses of woven steel fiber reinforced thermoplastic laminated composite plates subjected to transverse uniform load

This paper is concerned with the numerical results of the elasto-plastic stress analysis and residual stresses in woven steel fiber reinforced thermoplastic laminated composite plates for transverse uniform loads. The effects of ply number, orientation angle and bonding type on the residual stresses of laminated composite plates are investigated. Elasto-plastic stress analysis is carried out in the laminated plate by using the finite element technique. The finite element code ANSYS is used to perform the numerical analyses using an eight-node layered shell element. Yielding loads and residual stresses are obtained for symmetric and anti-symmetric laminated plates with simply supported boundary conditions. Different stacking sequences of laminated composites are used in analysis and the results are compared with each other. Three load steps are carried out for each analysis consecutively. In the first load step, the yielding transverse load is applied. Secondly, a series of load increments is added until the load reaches "Yielding Load+ 0.005 NIPa". In the last step the external load is released to obtain the residual stress components. (C) 2003 Elsevier Ltd. All rights reserved

A study of the effects of various geometric parameters on the failure strength of pin-loaded woven-glass-fiber reinforced epoxy laminate

The aim of this study is to examine the effects of woven fiber, specimen width-to-hole diameter ratio (W/D), and the ratio of edge distance to hole diameter (E/D) on the bearing strength of woven laminated composites. Glass/epoxy composites were manufactured under pressure by moulds at 120 degreesC. The mechanical properties and strengths of the composites were obtained experimentally. The glass/epoxy woven composites were loaded through pins. Single-hole pin-loaded specimens were tested for their tensile response and W/D and E/D ratios evaluated. Failure propagation and failure type were observed on the specimens. The influence of the joint geometry on the strength of the pin-loaded composites was assessed. The experimental results show that the ultimate load capacity of woven-glass-fiber. reinforced epoxy laminates with pin connections was increased by increasing W and E. However increasing the E/D ratio beyond 2 and increasing the W/D ratio beyond 3 have an insignificant effect on the ultimate load capability of the connection. (C) 2001 Published by Elsevier Science Ltd. All rights reserved

Analytical study of clamped steel fiber reinforced aluminum metal matrix composite including elasto-plastic behavior

The elasto-plastic behaviour of steel fiber reinforced aluminum metal matrix composite with five different orientations has been investigated, including the effect of single force. A composite beam with a rectangular cross section is fixed at one end and is bent by a transverse force P applied to the free end. To determine analytically, residual stresses and the expansion of plastic zone for different orientation angles a software program is developed and this program makes it possible to establish elastic region, plastic region, the distributions of the residual stress component, the distance between the free end and yield points for 0degrees, 30degrees, 45degrees, 60degrees and 90degrees orientation angles. To verify the analytical solutions, the sophisticated finite element code such as ANSYS 5.6 was used to perform numerical analyses

The response of laminated composite plates under low-velocity impact loading

This paper is concerned with evaluation of the in-plane dimensional effect of fiber-reinforced laminated composites under low-velocity impact. (0/90/0/90), oriented cross-ply E-glass/epoxy laminates studied were manufactured and all of the material parameters of laminated composite materials were measured experimentally. The impact testing was conducted with a specially developed vertical drop-weight testing machine. Impact tests were performed at impactor masses of 135 and 2600 g and an impact velocity of 3 m/s, The Studies were carried out on plate dimensions of 150 mm x 150 mm, 150 mm x 100 mm and 150 mm x 50 mm with two opposite sides clamped and the other two free and impact load applied at the center of each plate. A numerical simulation was performed using 3DIMPACT transient dynamic finite element analysis code for calculating stresses and contact forces of the composite plates during impact along with a failure analysis for predicting the threshold of impact damage and initiation of delaminations. (C) 2002 Elsevier Science Ltd. All rights reserved

Yeni Eubiyotik Katkı Madde Testleri: Ticari Çiftlik Koşullarında Sağlık ve Verim Üzerine Etkiler

Bu çalışmada mikrobiyal fermentasyon ile canlı probiyotik, organik asit, enzimler ile organik kökenli vitamin ve mineral maddeler içeren üç yeni eubiyotik katkı maddesi geliştirilmiştir. Araştırmalar 2015-2017 yılları arasında yürütülmüştür. Bunlardan birisi, özellikle fermentasyon sonunda katılan esansiyel ekstrakt kaynağı olarak öğütülmüş bitki içermektedir. Yumurtacı tavukların karma yemlerine %0,02 ile %0,1 arasında eubiyotik 1 katkısının yumurta verimi ve yumurta ağırlığı önemli şekilde artırdığı görülmüştür. Farklı işletmelerde barındırılan süt sığırlarına aynı katkıdan günde 15 gram (bir dizi ön test sonuçlarına göre bu doz etkili olmuştur) yedirildiğinde ise 1-3 kg arasında inek başına süt verimi artışı sağlanmıştır. Yeni doğan buzağılara sütle 15 g yedirildiğinde daha hızlı büyüme sağlanmış, ishal olan kuzu ve buzağılarda ishal vakasına 6 ile 24 saat içerisinde rastlanılmamıştır. Metabolik rahatsızlıklara sahip ergin sığırlara günde iki kere 75 g'lık doz su veya süt ile verildiğinde hayvanlar eski sağlık durumlarına 24 saat içerisinde girmiştir. Eubiyotik 1 karşımından et tipi piliçlere %0.5-1.0 dozlarında rasyon ile verildiğinde ise yemden yararlanma ve büyüme hızı önemli derece artmıştır. Et sığırlarına günde 20 g eubiyotik 2 karışımı verildiğinde günlük canlı ağırlık artışında 250 g daha fazla kazanç sağlanmıştır. Eubiyotik 3 karışımı 10.000 ton mısır silajına katıldığında silajlar 15 ile 30 gün içerisinde olgunluğa ulaşmıştır. Tüm bu yararlı etkilerin bu yeni ürünlerin değişik aktif maddeler içermesinden kaynaklandığı sonucuna varılmıştır. Ayrıca, bu ürünler tamamen doğal kökenli ve hiçbir zararlı etkisine rastlanılmamış olup en faydalı dozların etlik piliçlerde rasyonun %0.5, yumurtacı rasyonlarında 200-1000 mg/kg, süt ineklerinde günde 30 g/baş, buzağı ve genç hayvanlarda 15 g/baş, metabolic rahatsızlıklarda 75 g/baş ve silaj katkı maddesi olarak ton başına 1 g olarak tespit edilmiştirA microbial fermentation process was developed to produce three eubiotic products containing probiotics, organic acids, enzymes, organic vitamins and minerals. The studies were carried out from 2015 to 2017. One product was specifically added with ground leaves of essential oil plant at the end of fermentation. As a result of this study, a dose of Eubiotic 1 ranging from 0.02 to 0.1% of diet remarkably increased egg yield and egg weight of laying hens. A daily increase of 1 to 3 kg milk per cow with no increase in dry matter intakes was obtained from a dose of 15 g eubiotic 1 per head per day in several farm trials. Calves had a 15 g Eubiotic 2 in warm milk grew faster than those given no supplement in milk. Calves and lambs having a severe level of diarrhea provided with 15 g supplement of eubiotic 2 in milk showed no sign of diarrhea after 6 or 24 h. Dairy cows and beef cattle having severe and acute metabolic disorders administrated with a dose of 75 g eubiotic 2 per cow per twice a day had no signs of such disorders in 24 h. Meat-type broiler chickens and quails given a diet of 0.5% supplement produced more profitable meat than those birds had no supplement. A 250 g live weigh gain with better feed conversion ratio (FCR) was obtained from the fattening beef cattle given a 20 g/day/head of eubiotic 2. Eubiotic mixture 3 was a silage additive and added to approximately 10.000 tonnes of corn silages and then the maturation of silage occurred in 15 to 30 days. It was concluded that these beneficial effects were mainly due to the combination of various active agents, and the proposed dosages were 0.5% in broiler diet, 200-1000 mg/kg of laying hens, 30 g/head in dairy cow

Failure strength of woven glass fiber-epoxy composites pinned joints

In this paper, mechanical behavior and damage development of pin-loaded woven glass fiber-epoxy composites have been observed numerically and experimentally. Parametric studies have been performed to evaluate the effects of joint geometry and ply orientation on the failure strength and failure mode of composite laminates with a pin-loaded hole. For this purpose, a finite element program has been developed. The failure analysis was based on Hashin and Hoffman criteria that were applied at the ply level. The results (with Hashin and Hoffman criteria) were compared to each other. To verify to the numerical predictions of mechanical behavior, a series of experiments was performed with two different material configurations ([(0/90)(3)](S) - [(+/-45)(3)](S)) and twenty different geometries. The numerical and experimental results were compared and discussed. A good agreement between experimental results and numerical predictions was obtained