68 research outputs found
Studi Identifikasi Kerusakan Debonding Berbasis Respons Getaran Pada Struktur Kapal Berbahan Material Sandwich
No full textPenerapan material ringan pada struktur kapal menjadi strategi utama dalam meningkatkan kapasitas muat pada operasional kapal. Material sandwich adalah salah satu jenis material ringan yang memiliki potensi yang menjanjikan untuk diaplikasikan pada struktur kapal. Dalam studi penerapan material sandwich ringan pada kapal khususnya tipe hybrid sandwich masih memiliki banyak permasalahan yang disebabkan oleh masih rawannya terhadap berbagai cacat dan kerusakan karena proses manufaktur yang kompleks dan tingkat difusi yang rendah. Identifikasi kerusakan menjadi hal penting untuk menjamin kesehatan struktur dan isu keamanan operabilitas kapal. Oleh karena itu, pada tahap awal telah dilakukan kajian penerapan material hybrid sandwich dengan lokasi struktur yang beragam untuk melihat signifikansi keuntungan penerapan material sandwich secara teknis. Kemudian, pemodelan debonding secara numerik dengan eksperimen dilakukan pada pelat sandwich dan struktur lokal kapal untuk mengkaji hubungan parameter debonding terhadap respon dinamis. Dari respon dinamis yang didapatkan dari
analisis dinamis, algoritma identifikasi besar, lokasi, dan jumlah kerusakan dikembangkan dengan metode k-Nearest Neighbor dan Mode Shape Curvature (MSC) Square. Hasil penelitian menunjukkan kajian aspek teknik penerapan
material sandwich pada struktur kapal memiliki prospek yang menjanjikan dengan pengurangan berat maksimal 17% dan penurunan tegangan maksimal 28%. Selain itu, indeks kerusakan baik respon linear maupun nonlinear yang telah
dikembangkan berhasil menganalisis fenomena hubungan parameter debonding dengan respon dinamis. Pada tahap akhir, algoritma identifikasi besar kerusakan berhasil mendeteksi adanya debonding pada pelat sandwich dengan tingkat akurasi 97,6%. Selain itu, algoritma identifikasi lokasi kerusakan dengan metode MSC Square memiliki akurasi sebesar 99,43%. Pengembangan algoritma identifikasi besar dan lokasi kerusakan masih terbatas menggunakan bentuk debonding yang sensitif yakni squared debonding. Penelitian kedepan dengan bentuk debonding
yang lain dan metode algoritma yang lain perlu kajian lebih lanjut.
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The application of lightweight materials on the ship's structure is the main strategy in increasing the loading capacity of ship operations. Sandwich material is one type of lightweight material that has promising potential to be applied to ship structures. In the study of lightweight sandwich materials applications, especially
the hybrid sandwich type on ship structures, there are many problems caused by the sandwich structure which is still prone to various defects and damage due to complex manufacturing processes and low diffusion rates. The identification of damage becomes important to ensure the health of the structure and security issues. At the initial stage, the author conducted a study on the application of hybrid sandwich materials with various structural locations to see the significance of the
advantages of applying sandwich materials technically. Then, numerical debonding modeling with experiments was carried out on sandwich plates and local ship structures to examine the relationship between debonding parameters and dynamic response. From the dynamic response obtained from dynamic analysis, the identification algorithm of the magnitude and location of the damage was developed
using the k-Nearest Neighbor method and the Square Shape Curvature (MSC) Mode. The results showed that the study of technical aspects of the application of sandwich materials on ship structures has promising prospects with a maximum weight reduction of 17% and a maximum stress reduction of 28%. In addition, the damage indices for both linear and nonlinear responses that have been developed have succeeded in analyzing the phenomenon of the relationship between debonding parameters and dynamic responses. In the final stage, the damage identification algorithm succeeded in detecting the presence of debonding on the sandwich plate with an accuracy rate of 97.6%. In addition, the damage location identification algorithm with the MSC Square method has an accuracy of 99.43%. The development of the damage identification algorithm is still limited using a sensitive debonding shape. Future research with other forms of debonding and other algorithmic methods needs to be investigated
Pengembangan Model Permainan Untuk Meningkatkan Kemampuan Motorik Peserta Didik Sekolah Dasar
Get PDFPenelitian ini bertujuan untuk menghasilkan model permainan tradisional untuk meningkatkan kemampuan motorik anak sekolah dasar yang telah disusun dan disesuaikan dengan kurikulum serta karakteristik siswa sekolah dasar.
Prosedur pengembangan dalam penelitian model permainan menggunakan Research and Development yang diadopsi dari langkah-langkah Sugiyono (2015: 298), berikut langkah-langkah yang ditempuh sebagai berikut: (1) potensi dan masalah, (2) pengumpulan data, (3) desain produk, (4) validasi data, (5) validasi data, (6) uji coba produk, (7) revisi produk, (8) uji coba pemakaian, (9) revisi produk, (10) revisi produk.
Hasil penelitian pengembangan ini menghasilkan lima model permainan yaitu: (1) balap velg sepeda, (2) lempar karet gelang, (3) unclang karet gelang, (4) gandon botol air mineral, dan (5) bola target velg sepeda. Model permainan disusun dalam bentuk buku pedoman model permainan kemampuan motorik bagi peserta didik sekolah dasar. Berdasarkan penilaian para ahli materi dan guru sekolah dasar dapat disimpulkan bahwa model permainan untuk meningkatkan kemampuan motorik anak sekolah dasar sesuai dengan kurikulum dan karakteristik siswa sekolah dasar. Oleh karena itu model permainan ini dapat meningkatkan kemampuan motorik siswa sekolah dasar sehingga layak untuk digunakan dalam pembelajaran di sekolah dasar
Simulasi numerik kekuatan rak roket portabel menggunakan metode elemen hingga
No full textMakalah ini memaparkan tentang desain rak roket portabel dan analisis tegangan statik menggunakan simulasi numerik. Rangka rak roket portabel didesain untuk mampu membawa 5 unit roket. Pada penelitian ini, beban tiap roket divariasikan 150 kg, 175 kg, 200 kg, dan 225 kg. Material rangka rak roket portabel menggunakan Aluminium 6061-T6. Simulasi numerik dilakukan dengan bantuan perangkat lunak Autodesk Inventor Professional 2017. Hasil analisis tegangan statik menunjukkan tegangan von Mises maksimum rak roket portabel untuk variasi beban 150 kg, 175 kg, 200 kg, dan 225 kg berturut-turut adalah 96,41 MPa, 112,5 MPa, 128,54 MPa, dan 144,6 MPa. Rak roket portabel mampu menahan beban dinamik untuk beban tiap roket 200 kg karena memiliki faktor keamanan lebih dari 2
ANALISA EFFECTIVE WAKE FRICTION AKIBAT PENAMBAHAN STERN TUNNELS PADA KAPAL TROPICAL PRINCESS CRUISES MENGGUNAKAN METODE CFD (COMPUTATIONAL FLUID DYNAMIC)
No full textPeningkatan performa kapal harus dilakukan untuk menunjang kinerja kapal terutama kapal penumpang yang membutuhkan efisiensi berlayar yang baik. Salah satu cara meningkatkan performa kapal adalah dengan meningkatkan efisiensi sistem propulsi kapal dengan memusatkan aliran menuju propeller. Stern tunnels adalah modifikasi bentuk buritan kapal dengan membuat sebuah cekungan kedalam untuk memusatkan aliran air menuju propeller kapal. Dengan penambahan stern tunnels ini dapat meningkatkan performa kapal yaitu dapat meningkatkan kecepatan advanced (Va) kapal dan mengurangi nilai wake kapal. Stern tunnels dipasang pada dua sisi buritan kapal dengan menggunakan dua variasi yaitu ketinggian stern tunnels (Hw) dan panjang stern tunnels (L). Analisa perhitungan kecepatan advanced dan wake friction kapal menggunakan software berbasis CFD dengan menggunakan 9 titik koordinat probe. Dari analisa didapatkan hasil bahwa kedua belas model variasi tersebut dapat meningkatkan kecepatan advanced kapal dan mengurangi wake friction kapal. Model M dengan tinggi penambahan tinggi stern tunnels 0,2 m dan panjang stern tunnels 9 m adalah model yang memiliki kecepatan advanced terbesar dan wake friction terkecil dengan presentase peningkatan kecepatan advanced sebesar 4,927 % dan presentase pengurangan nilai wake sebesar 30,4
Advanced Development of Sensors’ Roles in Maritime-Based Industry and Research: From Field Monitoring to High-Risk Phenomenon Measurement
No full textThe development of human civilization over the last decade has reached a landmark as Industry 4.0 has been widely introduced. Several aspects of industry and manufacturing activities are changing due to the Internet of Things (IoT), location detection technologies, and advanced human–machine interfaces. To enact industrial affairs under those specifications, a sensor is required to transform physical events into numerical information. The use of sensors in marine applications also appears in research and studies, in which the sensor is used for both monitoring the phenomena of a designated subject and data acquisition. Achievements in quantifying complex phenomena in critical maritime designs are fascinating subjects to discuss regarding their development and current states, which may be reliable references for further research on developing sensors and related measurement analysis tools in marine, shipbuilding, and shipping fields. This comprehensive review covers several discussion topics, including the origins and development of sensor technology, applied sensor engineering in logistic and shipping activities, the hydrodynamic characterization of designed hulls, the monitoring of advanced machinery performance, Arctic-based field observations, the detection of vibration-based damage to offshore structures, corrosion control and monitoring, and the measurement of explosions on critical maritime infrastructures
Mechanical Properties Evaluation of Laminated Composites of Petung Bamboo (Dendrocalamus asper) and Coconut Coir Fiber as Ship Construction Components
Get PDFThe high demand for steel and wood as the primary shipbuilding materials will increase market prices due to decreasing supplies each year. To address this issue, new alternative materials that are more environmentally friendly and inexpensive, such as natural fibers like bamboo and coconut fiber, must be explored. This study aimed to investigate how the directional arrangement (0° unidirectional and 90° unidirectional) of laminated Petung bamboo (Dendrocalamus asper) affects the compressive and flexural strength of ship construction. The compressive strength on the X, Y, and Z-axis was measured to determine the laminated beam’s strength ratio on each side. In contrast, the flexural strength was only observed on the Y and Z-axis due to testing equipment limitations. The results showed that the directional arrangement of laminated Petung bamboo with different test axes significantly impacted the compressive and flexural strength of laminated beams made of Petung bamboo and coconut coir fiber. Laminated Petung bamboo and coconut coir fiber with 0° unidirectional fiber had better compressive and flexural strength values than those with 90° unidirectional fiber. Based on the data testing, the combination of Petung bamboo and coconut coir fiber materials can be categorized into different strength classes. These findings have important implications for using laminated bamboo in shipbuilding applications. The use of laminated bamboo with a 0° lamina direction could be recommended for ship components that require high levels of strength than laminated bamboo with a 90° lamina direction
Simulasi numerik kekuatan rak roket portabel menggunakan metode elemen hingga
No full textThis paper describes the design of a portable rocket rack and static stress analysis using numerical simulation. The portable rocket rack frame is designed to be able to carry 5 rockets. In this study, the load of each rocket was varied 150 kg, 175 kg, 200 kg, and 225 kg. The frame material for the portable rocket rack uses Aluminum 6061-T6. Numerical simulations were carried out with the help of Autodesk Inventor Professional software. The results of the static stress analysis show that the maximum von Mises stress for portable rocket racks for variations in loads of 150 kg, 175 kg, 200 kg and 225 kg, respectively, is 96.41 MPa, 112.5 MPa, 128.54 MPa, and 144.6 MPa. The portable rocket rack can withstand dynamic loads for each rocket of 200 kg because it has a safety factor of more than 2
THE CONVERSION STRATEGY FROM LANDING CRAFT TANK INTO LIVESTOCK CARRIER: AN OVERVIEW OF TECHNICAL EVALUATION AND ECONOMICAL BENEFIT
Get PDFThe conversion of Landing Craft Tank into Livestock Carrier as an alternative solution was conducted by performing technical and economic assessments. The conversion analysis of LCT vessels to Livestock Carrier was achieved by performing layout rearrangement, stability test, seakeeping, and resistance test to measure the technical change occurring due to the modification. The economic added-value analysis was conducted by calculating the payback period to determine the estimated time needed to recover the cost of an investment. The result showed that the conversion of LCT ships has a good technical assessment. The intact and damage stability performance qualifies the standard criteria given by the IMO standard. The motion result qualifies the standard according to the type of vessel in terms of heave, pitch, and roll motions. Moreover, the resistance of the Livestock Carrier is reduced due to a decrease in displacement and draft. In terms of economic assessment, the Livestock Carrier conversion project qualifies for investment projects and improves the use-value and economy of a business segment
Identification of Damage Size Effect of Natural Frequency on Sandwich Material using Free Vibration Analysis
Get PDFOne of the most innovative developments in the field of advanced materials is sandwich materials. Sandwich material applications need standard requirements to be applied to marine structures, especially on ship construction. Sandwich material research is conducted on a laboratory scale to obtain the appropriate material composition in its development. In the process of developing this material, the material can be damaged. Most damage occurs in the core material, which results in difficulties in the identification process. This study compares damage identification methods based on free vibration analysis on the side sandwich plate of the ship’s hull. Damage-based identification is carried out to determine the response of vibration to the damage that occurs. Moreover, the method in this research uses a numerical approach and experimental vibration measurement. Numerical modelling is used to determine the appropriate boundary conditions and is shifted in experimental measurement. Damage modelling assumes that the material experiences core failure with a numerous variation model. Quantification of damage on the core correlates with natural frequency reduction due to a decrease in the stiffness of the sandwich material. Hence, the difference in the deviation value is used to determine the accuracy of damage identification
Structural Assessment of Frame Design of 40-ft ISO LNG Tank under High and Low Cycle Load Conditions
No full textAs a leading global exporter of liquefied natural gas, Indonesia faces substantial logistical challenges in distributing LNG, primarily due to its archipelagic nature. As the primary distribution component, the strength and durability of the LNG ISO tank design for the Mini LNG Carrier is paramount because it must withstand the multifaceted and rigorous demands of multimodal operations spanning land and sea environments. This study examines the fatigue performance of 40-ft ISO LNG tank frame configurations under stationary and dynamic operational loads to obtain optimum strength-to-weight savings. Finite element analysis investigates the fatigue life of 4 proposed LNG tank frame designs under high-cycle and low-cycle conditions, adhering to the ASME and ISO 1496-3 standards guidelines. It can be found that the elimination of longitudinal, vertical, and horizontal frames can effectively reduce stress and displacement and reach 6% total weight saving. The study conclusively shows that in both low and high cycle loading, the fatigue damage factor (FDF) values are below the critical threshold, indicating all proposed frame designs likely achieve a 20-year service life
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