Hasil Pencarian  ::  Simpan CSV :: Kembali

"Ruang Lingkup dan metodologi: Alat bantu kerja yang bergetar untuk mempencepat proscs produksi di industri sangat banyak digunakan dan rutin digunakan setiap harinya. Oleh karena itu, perlu diketahui prevalensi hand-arm vibration syndrome (HAVS) pada pekerja ini serta melihat pula faktor-faktor yang berhubungan. Penelitian ini menggunakan desain potong lintang. Dengan teknik total sampling didapatkan 105 responden.Setiap responden dilakukan anamnesis, pemeriksaan fisik, pengukuran tingkat akselerasi alat yang digunakannya dengan vibration meter. Diagnosis HAVS dinilai pada dua tangan berdasarkan klasifikasi Stockholm. Penelitian dilakukan di bagian assembling PT X, Jawa Barat. Hasil dan kesimpulan: Dari hasil 105 responden bagian assembling PT X, Jawa Barat didapatkan 28(27,l8%) orang mengalami HAVS dalam berbagai stadium menuzut klasiiikasi Stockholm. Jenis alat yang digunakan responden terdiri dari berbagai jenis di setiap bagiannya. Bagian dengan alat yang paling besar dan berat terdapat di bagian chassis dengan rata-rata scberat 2,19 kg dengan SD 0,79 kg. Demikian juga dengan tingkat akselerasi alat yang bervariasi di tiap bagiannya dan bagian chassis pulg yang berakselerasi paling besar yaim sebesar 31,68 m/sz dcngan so 15,91 rn/s. Pekerja yang tidak mendapatkan pelatihan akan memiliki risiko sebesar hampir 7 kali untuk menderita HAVS (95% CI 2,18 - 2l,68, OR=7,44 dan p=0,00I). Penggunaan alat berakselerasi 12 m/sz atau lebih tinggi memiliki risiko HAVS sebesar hampir 6 kali lebih besar dibandingkan dengan yang berakselerasi kurang dari 12 m/s (95% Cl 0,68 - 48,26, OR= 5,74 dan p=0,l08). Dari penelitian ini dapat disimpulkan bahwa tidak adanya pelatihan tentang cara penggunaan alat bergetar merupakan risiko HAVS yang terkuat.

---

Vibrating tools are commonly instruments used in the industrial sector because of their effectiveness in shortened the time needed in the industrial process. Therefore, it is necessary to know the prevalence of Hand-Arm Vibration Syndrome as well as its association factors. This study used cross sectional design. Sample selection used total population technique. Interview, physical examination and tool acceleration measurement with vibration meter, were administered in every respondent. HAVS was diagnosed for each hand according to Stockholm classification. The study was conducted in assembling department of car factory *X* in West Java near the workers workplace.

Results, conclusion and suggestion: Out of 105 respondents, 28 (27.l8%) suffered from HAVS according to Stockholm classification. The respondents use many types of tools in each sub department. Chassis sub department showed the heaviest vibrating tools (mean 2.19 kg, SD 0.79 kg) as well as the highest acceleration (31.68 m/sz, SD 15.91 m/sz). Statistically, there were not any significant association between tools weight and the occurrence of HAVS. However, training program showed significant association with HAVS (OR=7.44 95% Cl 2.41 - 22.98, p<0.00l). The absence of training increased the risk of HAVS almost 7 times than those who joined the training (95% CI 2.18 - 21.68, 0R=7.44 and p=0.001). The usage of tools with acceleration 12 rn/sz or higher increased the risk of HAVS almost 6 times than those below 12 m/sz (95% CI 0.68 _ 48.26, oR= 5.14 and p=o.1os). n is concluded that the absence of training program was the strongest risk factor of HAVS."

"Electromagnetic vibration energy harvesting devices introduces an optimization approach which is applied to determine optimal dimensions of the components (magnet, coil and back iron). Eight different commonly applied coupling architectures are investigated. The results show that correct dimensions are of great significance for maximizing the efficiency of the energy conversion. A comparison yields the architectures with the best output performance capability which should be preferably employed in applications. A prototype development is used to demonstrate how the optimization calculations can be integrated into the design?flow. Electromagnetic vibration energy harvesting devices targets the designer of electromagnetic vibration transducers who wishes to have a greater in-depth understanding for maximizing the output performance."

"This volume contains the contributions to the 10th International Workshop on Railway Noise, held October 18–22, 2010, in Nagahama, Japan, organized by the Railway Technical Research Institute (RTRI), Japan. With 11 sessions and 3 poster sessions, the workshop featured presentations by international leaders in the field of railway noise and vibration. All subjects relating to 1. prospects, legal regulation, and perception ; 2. wheel and rail noise ; 3. structure-borne noise and squeal noise ; 4. ground-borne vibration ; 5. aerodynamic noise and micro-pressure waves from tunnel portals ; 6. interior noise and sound barriers ; and 7. prediction, measurements, and monitoring are addressed here."

"This work presents a unified approach to the vibrations of elastic systems as applied to MEMS devices, mechanical components, and civil structures.Applications include atomic force microscopes, energy harvesters, and carbon nanotubes and consider such complicating effects as squeeze film damping, viscous fluid loading, in-plane forces, and proof mass interactions with their elastic supports. These effects are analyzed as single degree-of-freedom models and as more realistic elastic structures. The governing equations and boundary conditions for beams, plates, and shells with interior and boundary attachments are derived by applying variational calculus to an expression describing the energy of the system. The advantages of this approach regarding the generation of orthogonal functions and the Rayleigh-Ritz method are demonstrated.A large number of graphs and tables are given to show the impact of various factors on the systems’ natural frequencies, mode shapes, and responses."

"Kebutuhan akan produk yang terminiaturisasi telah meningkat tinggi di era konsumer dengan tuntutan tinggi dan dengan tren yang selalu berubah. Hal ini juga yang membuat perkembangan teknologi mikromanufaktur terjadi secara cepat untuk memenuhi kualitas produk yang diinginkan. Salah satu dari teknologi yang dikembangkan ini yaitu ultrasonic vibration assisted machining (UVAM). UVAM berbeda dengan pemesinan konvensional dikarenakan adanya fenomena engage -disengage dari alat potong terhadap benda kerja. Fenomena engage-disengage menghasilkan geometri chip yang berbeda, sehingga menghasilkan permukaan hasil pemesinan yang berbeda juga. Penelitian ini bertujuan untuk mempelajari bagaimana UVAM dapat memberikan kualitas yang lebih baik dibandingkan dengan pemesinan konvensional. Pendekatan yang dilakukan yaitu dengan menghitung posisi cutting edge relatif terhadap benda kerja, baik itu sebelum maupun setelah diaplikasikannya getaran. Simulasi model teoritis dibuat dan dipresentasikan dengan menggunakan MATLAB. Tidak hanya parameter pemotongan dan parameter getaran saja, pengaruh fitur geometri cutting edge juga dipertimbangkan dalam penelitian ini. Sistem UVAM yang digunakan adalah dua dimensi (2D) dan diaplikasikan pada benda kerja. Dari hasil analisis, model yang dikembangkan dapat merepresentasikan geometri chip dan geometri permukaan dari hasil proses UVAM.

---

The needs of miniaturized products have increased a lot in this ever-changing era. This also makes the micromanufacturing technologies develop fast in order to meet the required quality of a product. One of the developed technologies is ultrasonic vibration assisted machining (UVAM). UVAM is different than conventional machining because of the way the cutting tool and the workpiece engage and disengage. This engage and disengage phenomenon produces a different chip geometry, hence also produces a different machined surface geometry.

The purpose of this sstudy is to give an understanding about how UVAM can have several advantages compared to conventional machining. The approach used in this study is by calculating where the cutting edge position relative to the workpiece, before and after vibration is applied. Simulated theoritical models are made and presented using MATLAB. Not only cutting parameters and vibration parameters, the influence of the geometry feature of cutting edge is also considered in this study. The UVAM system used is two-dimensional (2D) and induced on the workpiece. From the analysis result, the developed model can present the geometry of chip and geometry of machined surface from UVAM proccess."

"Musculoskeletal disorders (MSDs) merupakan cedera dan gangguan yang mempengaruhi pergerakan tubuh manusia atau sistem muskuloskeletal. Salah satu penyebab dari keluhan MSDs adalah getaran (whole body vibration). Driver ojek online yang mempunyai aktivitas berkendara setiap hari mempunyai risiko untuk terpajan getaran. Tujuan dari penelitian ini adalah untuk menganalisis hubungan antara pajanan getaran (whole body vibration) dan keluhan MSDs pada driver ojek online di Jakarta tahun 2019. Penelitian ini merupakan penelitian kuantitatif dengan menggunakan desain studi cross sectional. Populasi dalam penelitian ini adalah driver ojek online region Jakarta, dengan total sampel sebanyak 42 orang untuk menggambarkan keluhan MSDs dan 30 orang untuk menganalisis hubungan antara whole body vibration dengan keluhan MSDs. Instrumen penelitian yang digunakan adalah kuesioner Nordic Body Map and vibration meter. Hasil penelitian menunjukkan bahwa daerah tersering yang mengalami keluhan MSDs pada pekerja driver ojek online adalah pinggang bawah (76,2%), pantat (78,6%), bahu kanan (47,6%), bahu kiri (47,6%), dan pergelangan tangan kanan (45,2%). Pada penelitian ini diketahui bahwa usia, IMT, masa kerja, durasi pajanan kerja, frekuensi kerja, dan whole body vibration belum cukup berpengaruh dalam menyebabkan keluhan MSDs.

---

Musculoskeletal disorders (MSDs) are injuries and disorders that affect the movement of the human body or the muculoskeletal system. One of the causes of musculoskeletal disorders complaints is vibration. Online motorcycle drivers who drive every day have the risk to exposed by vibration. This study aimed to analyze the relationship between vibration exposure, especially whole-body vibration and musculoskeletal disorder (MSDs) complaints on online motorcycle drivers in Jakarta, 2019. This research is a quantitative study using a cross-sectional study design. Respondents were Jakartas Online motorcycle drivers, with the total number of samples was 42 drivers to describe the musculoskeletal disorders complaints and 30 drivers to analyze the relationship between whole body vibration and musculoskeletal disorders. Data was collected by the Nordic Body Map questionnaire and vibration meter. The results showed that the most pain complaints found in the upper buttocks (76.2%), lower buttocks (78,6%), right shoulder (47,6%), left shoulder (47,6%), and right wrist (45,2%). There was no a significant relationship between age, body mass index, working period, exposure duration, working frequency, and whole body vibration with musculoskeletal disorders complaints."

"This book comprises select proceedings of the International Conference on Future Learning Aspects of Mechanical Engineering (FLAME 2018). The book discusses different topics of industrial and production engineering such as sustainable manufacturing systems, computer-aided engineering, rapid prototyping, manufacturing management and automation, metrology, manufacturing process optimization, casting, welding, machining, and machine tools. The contents of this book will be useful for researchers as well as professionals. "

"Functionally Graded Materials (FGMs) merupakan material komposit dengan komposisi material bergradasi. Laporan ini membahas mengenai evaluasi statis, getaran bebas, dan tekuk pada balok FGMs dengan menggunakan salah satu Metode Elemen Hingga (MEH), yaitu elemen Mixed Quadratic Beam (MQB). Elemen MQB (Mixed Quadratic Beam) merupakan elemen hibrida dua nodal. Jurnal ini diawali dengan penjabaran formulasi eleman MQB yang diikuti oleh analisis hasil perhitungan numerik kasus statis, getaran bebas, dan tekuk pada balok FGMs menggunakan formulasi tersebut. Komputasi numerik dilakukan dengan menggunakan program MATLAB. Analisa statis, getaran bebas, dan tekuk pada balok FGMs dilakukan dengan menyelesaikan beberapa kasus balok dengan berbagai perletakkan, yaitu sendi-rol, jepit-bebas, dan jepit-jepit. Dari analisa tersebut, dapat disimpulkan bahwa program numerik yang dilandasi dengan formulasi elemen MQB untuk penyelasaian kasus statis, getaran bebas, dan tekuk pada balok FGMs menunjukkan nilai yang valid untuk balok dengan jumlah elemen yang banyak.

---

Functionally Graded Materials (FGMs) is a composite material with gradients of material composition. This thesis discusses about static evaluation, free vibration, and buckling of FGMs beams using an element of Finite Element Method, Mixed Quadratic Beam (MQB) element. MQB (Mixed Quadratic Beam) element is a two nodes hybrid element. This journal begins with formulation of MQB element then followed by numerical analysis of static, free vibration, and buckling on FGMs beams problems by using this formulation. Numerical computations are done using MATLAB software program. Static, free vibration, and buckling analysis of FGMs beams are done by solving several problems with various boundary conditions; simply supported, clamped-free, and clamped-clamped. From the analysis, it can be concluded that the numerical program to solve static, free vibration, and buckling of FGMs beams problems based on the formulation of MQB element shows good results for beams with large number of mesh.

"