Finite Element Simulation of a Steady-State Stress Distribution in a Four Stroke Compressed Natural Gas-Direct Injection Engine Cylinder Head

The main aim of this work is to predict the design performance based on the stress/strain and thermal stress behaviour of cylinder head under various operating conditions. The effects of engine operating conditions such as combustion gas temperature and maximum internal pressure, components initial temperature and engine speed on the stress and thermal stress behaviour of the cylinder head have been analyzed. The analysis was carried out using a finite element analysis (FEA) software package, MSC.NASTRAN which is use to simulate and predict the von-Mises stress and strain pattern and thermal distribution of the cylinder head structure during the combustion process in the engine and the geometry modelling was carried out using a popular computeraided engineering tool, CATIA V5. The result can be used to determine the quality of the design as well as identify areas which require further improvement. In this investigation, structural analyses of the cylinder head highlight several areas of interest. The maximum stress is found not exceeding the material strength of cylinder head, and thus the basic design criteria, namely no yielding and no structural failure under firing load case, can be satisfied. In addition, the effect of thermal stress/strain provides a good indication on structural integrity and reliability of the cylinder head, which can be improved in the early stages of design. This steadystate finite element method (FEM) stress analysis can play a very effective role in the rapid prototyping of the cylinder head

Studi Hutan Kota sebagai Penyedia Jasa Lingkungan pada Musim Hujan di Kota Malang

Malang merupakan kota yang identik dengan dingin. Dengan bertambahnya jumlah manusia menyebabkan banyak lokasi Ruang Terbuka Hijau yang mulai dialih fungsikan. Hutan kota yang berada di kota Malang memiliki banyak potensi alam yang berfungsi sebagai daerah penyangga, dan sebagai wadah ekosistem flora dan fauna yang dilindungi (Departemen Kehutanan, 2010). Penggunaan serangga sebagai bioindikator akhir-akhir ini dirasakan semakin penting dengan tujuan utama untuk menggambarkan adanya keterkaitan dengan kondisi faktor biotik dan abiotik lingkungan (Speight et al., 1999). Penelitian dilaksanakan bulan Januari sampai dengan Februari 2015 di Hutan Malabar dan Taman Kota Jalan Jakarta kota Malang. Setiap lokasi pengamatan dibagi menjadi 4 kuadran. Dari hasil penelitian diketahui bahwa pada Hutan Kota Malabar memiliki jasa lingkungan yang lebih baik dibandingkan dengan Taman Kota Jalan Jakarta. Hal ini dapat dilihat dari jenis vegetasi yang lebih beragam 60 untuk Hutan Kota Malabar dan 40 untuk Taman Kota Jalan Jakarta. Beragamanya jenis vegetasi menyebabkan suhu yang berada pada Hutan Kota Malabar menjadi rendah sehingga menghasilkan kondisi yang lebih sejuk. Jika dibandingkan dengan data BMKG kota Malang, Hutan Kota kota Malabar memiliki suhu yang lebih rendah, hal ini berarti kandungan O2 pada Hutan Kota Malabar lebih tinggi. Banyaknya pohon yang berbatang besar juga membuat penyerapan air pada musim hujan tinggi sehingga tidak terjadi banjir. Jasa lingkungan lain yang diberikan Hutan Kota Malabar adalah dengan memberikan tempat yang sesuai untuk perkembangbiakan serangga arboreal

The impact damage response of plain woven natural silk/epoxy laminated composite plates

MoscowGrayscaleForman Nitrate Negatives, Box

Technical and vocational education students’ perception of using learning videos during Covid-19 pandemic period

The closure of Higher Education Institutions and Schools due to COVID-19 pandemic has affected the structure of Learning and Teaching (T&L) from direct method at institutions to Open and Distance Education (ODE) completely. All face-to-face T&L activities are not allowed except for certain categories of students who need to return to campus in stages to participante in T&L activities in full compliance of the Standard Operating Procedures (SOP) set by prioritizing safety measures and social distancing. This study used a quantitative approach by using online questionnaire as instrument (google form). A total of 73 Technical and Vocational Education (TVE) students from various backgrounds of respondents participated in the study. The findings of the study showed that there was a strong correlation between the aspects of interest and gender of TVE students in using learning videos during the COVID-19 pandemic period (r = .701). Therefore, all parties must prepare to face the new norm, namely the ODL method as a whole during the COVID-19 pandemic period to continue the T&L process for students

Correlation Between Cutting Force and Residual Stress in Dry End-Milling of Inconel HX

Residual stress in the end-milled subsurface can significantly affect the fatigue performance of end-milled material. In the end-milling process, the generation of residual stress is extremely complex, which is closely related to the spindle speed, feed per tooth and cutting force. Thus, it is crucial to elucidate the influence of spindle speed and feed per tooth on cutting force and residual stress, also the correlation between cutting force and residual stress in terms of spindle speed and feed per tooth. According to this, dry end-milling of Inconel HX was performed by climb-milling using Kennametal KYS40 solid ceramic end-mill. From this experimental test, cutting force and residual stress showed a U-shaped relationship with the increase of spindle speed, while cutting force and residual stress showed a linear relationship with the increase of feed per tooth. Furthermore, for low cutting force and residual stress, the focus should be on choosing the optimum combination of spindle speed (21,400 to 24,100 rpm) and feed per tooth (0.014 to 0.016 mm/tooth)

Correlation Between Cutting Force and Residual Stress in Dry End-Milling of Inconel HX

Residual stress in the end-milled subsurface can significantly affect the fatigue performance of end-milled material. In the end-milling process, the generation of residual stress is extremely complex, which is closely related to the spindle speed, feed per tooth and cutting force. Thus, it is crucial to elucidate the influence of spindle speed and feed per tooth on cutting force and residual stress, also the correlation between cutting force and residual stress in terms of spindle speed and feed per tooth. According to this, dry end-milling of Inconel HX was performed by climb-milling using Kennametal KYS40 solid ceramic end-mill. From this experimental test, cutting force and residual stress showed a U-shaped relationship with the increase of spindle speed, while cutting force and residual stress showed a linear relationship with the increase of feed per tooth. Furthermore, for low cutting force and residual stress, the focus should be on choosing the optimum combination of spindle speed (21,400 to 24,100 rpm) and feed per tooth (0.014 to 0.016 mm/tooth)

Handover Algorithm based VLP using Mobility Prediction Database for Vehicular Network

This paper proposes an improved handover algorithm method for vehicle location prediction (VLP-HA) using mobility prediction database. The main advantage of this method is the mobility prediction database is based on real traffic data traces. Furthermore, the proposed method has the ability to reduce handover decision time and solve resource allocation problem. The algorithm is simple and can be computed very rapidly; thus, its implementation for a high-speed vehicle is possible. To evaluate the effectiveness of the proposed method, QualNet simulation is carried out under different velocity scenarios. Its performance is compared with conventional handover method. The superiority of the proposed method over conventional handover method in deciding the best handover location and choosing candidate access points is highlighted by simulation. It was found that VLP-HA has clearly reduced handover delay by 45% compared to handover without VLP, give high accuracy, hence low complexity algorithm

Analysis of a Metal Matrix Composites Automotive Component

This study presents an implementation of concurrent engineering (CE) and an analytical network process to form a new rating method as part of the manufacturing process and material analysis in the product development environment. The proposed procedure is referred to as a concurrent network (CN). It is planned for CN to carry out simultaneous analysis of all aspects of product elements by using CE strategy. Furthermore, CN enables interdependence and interrelationship analysis between product elements by implementing ANP. In this study, CN is utilized for the manufacturing process and material analysis of a metal matrix composites (MMCs) automotive component which is the brake disc. The results show that by using CN, all the product parameters can be analyzed comprehensively and the importance weights of the product parameters with regard to the MMCs brake disc performance are obtained. It is concluded that in the manufacturing process cluster the primary process parameter has the highest score, while in the material cluster the ranking is dominated by mechanical properties. This means that these sub-conceptual parameters are the most important ones to consider in order to achieve the required performance of the product