Advances in Science and Technology Vol. 136

Abstract: This paper presents a design of the 1 degree-of-freedom (DOF) compliant mechanism to support rotation, which can be used as the compliant bearing in rotary motor. With the simple idea of replacing the traditional bearings with the compliant counterparts, the compliant motor built by the developed mechanism is capable of creating frictionless and repeatable rotations for precise applications. The compliant bearing is synthesized based on a specific connection of beam-type flexures; its stiffness characteristic is analytically determined in this paper. Finite element analysis (FEA) is then used to verify the analytical results. The correctness of the bearing design is demonstrated through the small deviation between the analytical and FEA methods. With the simple structure of this compliant mechanism, a low-cost flexure-based bearing can be achieved to support rotary motions in precision devices such as actuators, sensors, positioners, etc.

Abstract: Wing-In-Ground (WIG) Effect Vehicle can be differentiated into manned and unmanned aerial vehicle. These aircraft are designed in aerodynamic shapes to enables them to glide at low altitude above the sea surface. Proper design of wings and stabilizer is crucial to provide effective lifting force with minimum total body weight. A study was conducted to determine the orientation and shape of the wing and stabilizer for a new WIG Effect vehicle prototype. Three-dimensional modeling and air flow analysis were carried out to analyze the lifting force generated under the provided body construction materials and total gross weight. In this study, two wing designs and wing orientations were studied since the WIG Effect vehicle is not equipped with wing aileron or wing flap. The first design is called as original design which suggested by industrial fabricator and the second design is called as modified design suggested from this study for design improvement. The modified wing exhibited the largest lifting force, which applied the Bernoulli’s Principle in the design. Modified wing at 20° angle of attack has been selected as the best orientation of wing.

Abstract: This paper presents the development of a low-cost linear motor with precise – frictionless motion. The motor is constructed by two main modules: Compliant bearing and voice coil actuator (VCA). The mechanical property of the bearing is determined by its 6×6 stiffness matrix which is formulated based on the relationships between beam-type flexure elements within a compliant mechanism. To run the motor, a VCA is specifically designed to fit the desired dimensions and able to create enough input force for compliant bearings to reach their largest elastic deformation. Subsequently, the finite-element-analysis (FEA) is conducted to evaluate the performance of the motor through the simulations of bearing deformation and electromagnetic force from the VCA. The good agreement between analytical and FEA results demonstrates the correctness of the proposed design. With the low-cost due to the simple structure and the ability to produce frictionless motion, the motor presented in this paper can be considered as a potential candidate for the development of various applications in precision engineering field.

Abstract: FRP composite materials are still being continuously developed and researched, because FRP composite materials are non-magnetic and have good wave permeability, which can effectively achieve stealth and reduce the chance of being attacked. The underwater explosion impact of warships is a severe high-strain rate response. At present, most of the structural response simulations of underwater explosions are simulated with static material parameters. The static material parameters and dynamic material parameters in the tensile direction are obtained through the MTS material testing machine and the Hopkinson bar, and the other direction material parameters are obtained with Compose IT developed by BV certification. The results show that under the dynamic material parameters of LT800/M225 composite material with high strain rate, the stress and strain are both higher than those of the static test, and the stress-strain curves also have obvious differences in trends. Obtain the static and dynamic material parameters of LT800/M225, use ABAQUS to simulate the underwater explosion of the simplified ship model, and use the Tsai-Hill failure criterion to judge the material damage. The research results show that the failure time of the static or dynamic material parameters is similar, but the strain response of the dynamic material parameter simulation is more obvious than that of the static material parameter analysis. The research results of this paper can be used as a reference for subsequent research by composite material structure designers.

Abstract: This study develops a mathematical model to optimize the partial delivery components allocation. This is one of a tactic of planning that be needed in a supply disruption situation. The new model considers the secondary supplier as a buffer. The order is triggered as soon as the primary supplier is disrupted. However, the component price is usually higher than buying from the primary supplier. Thus, we must investigate the model’s performance compared to existing allocation schemes. The mathematical model is linear programming and coded in AMPL language. The real-industrial data were excerpted and tested on a cloud computing service. The result was compared in terms of the total cost with the conventional value-at-risk policy, fair allocation scheme, and the company’s practice, the greedy procedure. The proposed method yields a lower total cost compared to other allocation schemes.

Abstract: In the HVAC system, the required energy consumption is very large so that energy saving processes are needed. One effective method in this energy saving process is the heat recovery process using a Heat Pipe Heat Exchanger. Various studies have been carried out regarding the application of HPHE in HVAC systems to reduce temperature and maintain air humidity. In its application, there are many factors that affect the effectiveness of using this HPHE. Therefore, in this research, an optimization process will be carried out by considering the number of HPHE modules, inlet air temperature, and inlet air velocity. The modelling is performed to predict energy recovery and payback period by using Response Surface Methodology (RSM). Optimization study was conducted to investigate the optimum energy recovery and payback period by varying HPHE parameters experiment.

Abstract: This article includes a car-use thermoelectric cooler and a generator driven by exhaust heat. Due to space constraints, automotive air conditioning systems are driver-oriented. The researcher invented a thermoelectric air conditioner that cools the back seat roof. The cooler is quiet and easy to assemble. The cooler was powered by an exhaust-pipe-mounted thermoelectric generator. The thermoelectric generator and cooler were incorporated into a storage device to provide continuous power to the cooler. A DC-DC Converter lets us store exhaust pipe heat energy and use it to cut household energy demand. This saves electricity and is eco-friendly. This study will design a thermoelectric system to improve automotive systems and reduce the environmental impact of vehicle waste heat, which can contribute to global warming.