Bambang Suhardi

Standard tube selection for recumbent bicycle frame using simulated finite element analysis

The number of bicycle users are increasing significantly, however many of bicycle designs are not suitable with urban condition. Generally, the urban road is smooth and flat, but there are many junction and trafic, so that a city bicycle should be specifically designed for that condition. Department of Industrial Engineering has conducted a research focused on the ergonomics city bicycle. The result of research is the recumbent bicycle using Short Wheel Base (SWB) was selected as the best concepts instead of upright bicycle. The research has continued to develop its compatibility with standard bicycle components to improve its manufacturability and maintainability which eventually resulted a first bicycle prototype. We keep steel as its frame material because it has low price, high manufacture ability, high formability more than other materials that highly recomended for city bicycle. Unfortunately, the frame weight of the prototype is still 50% heavier than the upright bicycle with the same steel frame material because the weight or frame tube geometry was not concerned in the previous researches. Basically, heavier frame cause higher energy consumption during riding and makes the rider more easily tired. Different from upright, a SWB recumbent bicycle has single main frame construction so that it needs thicker material for maintaining its strength and stiffness, but it is still necessary to find the best tube geometry which can provide both lightness and strength. This study aims to select 44.5 mm outer diameter 1020 DOM A513 standard round steel tube size for SWB recumbent bicycle frame material. This research uses simulated Finite Element Analysis (FEA) method with Autodesk Inventor to determine stifness and weight of each steel tube alternatives. As the result, the steel tube with wall thickness of 2.8 mm is selected to be the best material for SWB Recumbent Bicycle.

Ergonomic checkpoints as the base of stamping station work facilities improvement

Work productivity in the stamping station in Batik Merak Manis Laweyan is one of the key components to the business continuity. Using ergonomics checkpoints with results validated through a Focus Group Discussion, hand tools and machine safety was identified as the major area for production process improvement. This research aims to improve the production process by designing ergonomic work facilities. From observation, the hand tools and machine safety is primarily associated with the work table, the cooker table for the candle, and the batik stamp. In formulating the improved design, the rational method by Cross was used, specifically the four stages design process; clarifying objectives, establishing function (penetapan fungsi), setting requirements, and determining characteristics. Improved stamping stations work facilities such as the work table and batik stamps handle cover were designed, incorporating the workers need, ergonomic principles, and anthropometric measurement.

Further study on a short wheel base recumbent bike frame using simulated finite element analysis

Bicycle development as a mode of urban transport by considering the ergonomic and health aspects have been developed since 2011 by the Department of Industrial Engineering, Sebelas Maret University. Based on the result, we get that the Short Wheel Base Recumbent Bike selected as the best concept for an urban condition. Then the prototype was made. The results of the prototype, it was discovered that the bike has a high weight because of the structure of a frame that made from steel with a large size and thick material. We still use steel as the frame material because it has a low price, highly manufacture ability, high formability more than other materials and highly recomended for the material of the bike in the urban area. Because of these problem, the research has continued to get the standard tube using simulated finite element analysis (FEA) which eventually resulted the best tube geometry for SWB Recumbent Bike is rectangular steel tube 30 × 60 mm with the material wall thickness is 1.3 mm. But the results are not optimal because the size of the dropout on the main frame is not calculated. So we need more research to find the size of the main frame by calculating the size of dropout. This study aims to determine did use the size of underneath (25 × 50 mm) and with reduce the size of dropouts remain capable and safe in use for SWB recumbent bike frame material. This research same as before, use Autodesk Inventor to Simulation Finite Element Analysis. As the result, rectangular steel tube 25 × 50 mm with the reduction of the dropout still capable and safe in use for SWB Recumbent Bicycle.

Design of polishing tools for improving work posture in furniture industry

Work-related musculoskeletal disorders are one of the greatest occupational health concern today. Awkward working posture is a physical factor identified in occupational musculoskeletal injuries. As shown in the polishing process, workers must perform in awkward postures like stooping and squatting to reach the entire surface of the product. This study aims to determine how much risk arising from polishing process and propose improvements to it. Nordic Body Map Questionnaires is used to indicate the discomfort of the polishing working process. Rapid Entire Body Assessment (REBA) selected to provide postural analysis of observational assessment quickly and easily for whole activities (static and dynamic). Assessment of the working posture indicates a high level of risk to the value of REBA score of 9 to 10 and the action level 3, which means that it needs immediate improvement. Application simulation tools in the process showed a decrease in the level of risk shown by assessment scores REBA be 2 to 3 which indicates the level of risk is low. It can be concluded that this tool could be used as alternative solutions to reduce the risk of workplace improvements polishing process.

Design Specification Determination with Collaborative Approach for Indonesian Short Wheelbase Recumbent Bicycle

Determination of specification for product development is useful, as it includes an overview of product-related information. However, it is not an easy thing, especially for new and innovative product. In the view of designer as the subject who has never made the product, he needs to work closely with the manufacturer so that the concept can be designed to become a feasible product. In addition, in order to reduce product design life cycle and minimize design errors, the designer needs to communicate and collaborate with the manufacturer. This research proposes a design specification based on the paradigm of Concurrent Engineering (CE) from Collaborative Product Development (CPD) strategy in the development of a new ergonomically designed Short Wheel Base (SWB) Recumbent Bicycle. This collaborative process involved an expert from bicycle practitioner which already had experience in building custom bicycle. The result of this study is a frame set design of the bicycle which considers human anthropometry and the detail list of its components. Beside of that, the process of collaboration with practitioners bicycle produces 37% change in the components used and 3 changes in shape of design SWB Recumbent Bicycle.

Work climate and work load measurement in production room of Batik Merak Manis Laweyan

The work environment is everything around the labours that can affect them in the exercise of duties and work that is charged. In a work environment, there are workplace climate and workload which affect the labour in force carrying out its work. The working climate is one of the physical factors that could potentially cause health problems towards labour at extreme conditions of hot and cold that exceed the threshold limit value allowed by the standards of health. The climate works closely related to the workload accepted by workers in the performance of their duties. The influence of workload is pretty dominant against the performance of human resources and may cause negative effects to the safety and health of the labours. This study aims to measure the effect of the work climate and the workload against workers productivity. Furthermore, some suggestions to increase the productivity also been recommended. The research conducted in production room of Batik Merak Manis Laweyan. The results showed that the workplace climate and the workload at eight stations in production room of Merak Manis does not agree to the threshold limit value that has been set. Therefore, it is recommended to add more opening windows to add air velocity inside the building thus the humidity and temperature might be reduced.The work environment is everything around the labours that can affect them in the exercise of duties and work that is charged. In a work environment, there are workplace climate and workload which affect the labour in force carrying out its work. The working climate is one of the physical factors that could potentially cause health problems towards labour at extreme conditions of hot and cold that exceed the threshold limit value allowed by the standards of health. The climate works closely related to the workload accepted by workers in the performance of their duties. The influence of workload is pretty dominant against the performance of human resources and may cause negative effects to the safety and health of the labours. This study aims to measure the effect of the work climate and the workload against workers productivity. Furthermore, some suggestions to increase the productivity also been recommended. The research conducted in production room of Batik Merak Manis Laweyan. The results showed that t...

Conceptual design of wearpack with physiology detector feature based on wearable instrumentation

Every company in Indonesia is responsible for their worker health and safety condition as mentioned in UU No I year 1970. In manufacturing industries, there are many manual tasks dealing with high work load and risk, so that they require excellent concentration and physical condition. There is no ideal way to guarantee worker safety without a real time physiological monitoring. This paper reports our ongoing study in conceptual design development of worker’s clothing which is equipped with a wearable instrumentation system. The system is designed to detect and measure body temperature and pulse in real time. Some electrical components such as, LCD (liquid crystal display), LEDs (light emitting diode), batteries, and physiological sensors were assembled. All components are controlled by a wearable on board controller. LEDs is used as alert which can indicate abnormal physical conditions. The LCD was added to provide more detail information. TMP 36 and XD-58C were selected as the physiological sensors. Fina...

Designing size of batik shirt for male college student in Surakarta using anthropometric data (Case study: Male college student of industrial engineering major in Surakarta)

Batik is one of the Indonesian culture that is growing very fast, proved with inaugurated batik into the world cultural heritage by UNESCO. Batik should be developed in various aspects in order to meet the needs of consumers, one of them in batik shirt size aspect. But unfortunately in terms of size, batik still has the disadvantages, there are differences in male size batik shirt between one batik shop and other batik shop. This makes the performance of selling batik is not optimal because consumers have difficulty in finding the appropriate size of batik shirt with anthropometry, eg in shop A consumer obtains batik shirt with size M but when it is at the store B, this consumers gain size L. This will make consumers confused while looking for the appropriate batik shirt size based on their anthropometry. The author tried to make a proposal in batik shirt size corresponding with male college student anthropometric data of Industrial Engineering Major of Sebelas Maret University (UNS) and Muhammadiyah University of Surakarta (UMS) with K-Means cluster method to obtain the appropriate size. First determined the desired number of clusters which is four cluster size : S, M, L and XL. Then the anthropometric data of students grouped by cluster K-Means method to get male size batik shirt according to anthropometric data of male college student of Industrial Engineering Major in Surakarta.

Analysis of potential work accidents using hazard identification, risk assessment and risk control (HIRARC) method

Batik Merak Manis Laweyan is one of the batik industry in Surakarta, where in the production process there are the potential accidents. The company also has provided personal protective equipment to workers to minimize the risk, but in reality, not all workers use personal protective equipment. The purpose of this study was to analyze the potential hazards that may occur and determine root causes of the occurrence so as to minimize the number of occupational accidents. This research uses the method of Hazard Identification, Risk Assessment and Risk Control (HIRARC) in analyzing potential hazards that may occur in the workplace by identifying hazards, risk assessment, and rank the risks. The risks that have the highest ratings will then be analyzed using the method of Fault Tree Analysis to find out the root cause of the occurrence. The results showed that there were 15 potential hazards, where two potential hazards have a high-risk level, 6 potential hazards have a medium risk level and 7 potential hazards have a low-risk level. Two potential hazards with high risk, it is known that factors causing potential hazards are a factor of dye used, the use of personal protective equipment such as masks, or the space factor of production.

An investment allocation model for quality improvement to reduce component variances at manufacturer and supplier side to maximize the return on investment

Todays Challenge for many manufacturing companies is how to improve product quality and reduce the production cost of the products offered in the market. Quality improvement must be performed by a company to maintain its products competitiveness in the market. Quality improvement and cost reduction can be performed by allocating investments to reduce the value of the variance in the component of a product. The company will provide a target variance of assembled products that must be achieved with a minimum allocation of investment. The allocation also considers the ability of the machine and selected suppliers to reduce the variance. In this paper, we develop an optimization model to allocate investment provided by manufacturer to reduce component variances at the manufacturer and suppliers side. The objective function of the model is to maximize The Return on Investment (ROI).