Optimal Design of HGV Front Structure for Pedestrian Safety

This paper addresses a pedestrian safety design of front structure of Heavy Goods Vehicle (HGV) by two concepts; firstly by equipping a lower bumper stiffener structure under the front bumper and secondly by putting an airbag in front of the HGV front panel. In this study, HGV-pedestrian collision accident was simulated by the crash analysis solver MADYMO environment, where the HGV model with the speed of 20 km/h was collided with an adult male and with an adult female pedestrian, respectively. The bumper and lower bumper stiffener were varied their positions, while the airbag was adjusted the vent hole size and the position of airbag in front of front panel vertically. The pedestrian injuries that can be sustained during the simulation impact were limited at the critical body parts of head, chest, upper leg; an injury criteria of Head Injury Criterion (HIC), Thorax Cumulative 3ms Acceleration (C3ms) and peak loads of femur, respectively. Because of various parameters and constraints of initial conditions and injury thresholds, a multi-objective optimization design problem considered these main injury criterion is solved in order to achieve the best solution for this study. The results of optimized design parameters for each cases and conditions were obtained and the possibilities of the proposed concept were discussed

FUNCTIONAL MODELLING APPROACH IN THE DESIGN OF AN ELECTRICAL SHOE DRYER

Functional basis is a design language consisting of a set of functions and a set of flows that are used to form a sub-function. This paper presents the application of functional basis to develop a functional model during the conceptual design of an electrical shoe dryer. In this research, reconciled functional basis was employed to develop the functional model of the electrical shoe dryer. Later on, the means to achieve the required sub-functions are identified based on the designer’s experience. In the embodiment design stage the identified means of the required functions are arranged to form the final layout of the electrical shoe dryer. In conclusion, the application of functional basis in the development of an electrical sho

Railway Dynamics Analysis Using Lego Mindstorms

In recent years, the high speed railway vehicle dynamics performances have been studied and investigated in order to determine the ride comfort of the passengers. Most of the time, these researches were involving expensive and high end technology of data logging system to record and analyze the data. In this research, a low cost data logging system (Lego Mindstorms) is used to gather the data from accelerometer and gyro during experimentation. The study about the behaviour of railway vehicle in term of roll and vibrations at three perpendicular axes during running at the curve track is performed. Actual field run of railway vehicle data collection is performed on the available high speed railway vehicle operating from Kuala Lumpur International Airport (KLIA) to the Kuala Lumpur (KL) Sentral. The route selected consists of several curves which are important to study the dynamics performance of the vehicle. The results from experiment establishes the dynamics performances of the railway vehicle in term of passengers’ ride comfort. With the availability of the data logging system and sensors, the railway vehicle dynamics performance can be analyzed and monitored for future improvement of railway vehicle service and operation

The Effect of Nozzle Size on the Tensile and Flexural Properties of PLA Parts Fabricated Via FDM

The nozzle of a 3D printer extrudes molten filament onto the print surface. The detachable and adjustable nozzle of a 3D printer allows for the printing of lines of varying thickness. This study intends to investigate the effect of nozzle diameter on the tensile and flexural properties of printed specimens. The tensile and flexural specimens were prepared according to ASTM D638 Type 1 and ISO 178, respectively. After specimens were printed with nozzles having diameters of 0.3, 0.4, 0.5, 0.6, and 0.8 mm, tensile and flexural tests were conducted using an Instron 5585 machine. Each specimen was printed with 0.2 mm layer thickness, a line pattern, and 100 percent infill. Tensile and flexural behaviors of PLA specimens were comparable, according to the findings. Tensile and flexural strengths increase as nozzle diameter increases, but they are only effective up to a certain diameter. At a nozzle diameter of 0.6 mm, the maximum tensile strength was 33.32 MPa, and at a nozzle diameter of 0.5 mm, the maximum flexural strength was 76.76 MPa. The flexural strength decreases when using nozzles with diameters of 0.6 and 0.8 mm, and the tensile strength decreases when using a nozzle with a larger diameter (0.8 mm). Because the diameter of the nozzle has a significant impact on the mechanical properties of a part, it is crucial to choose the correct nozzle diameter for optimal mechanical properties

Review of Research on Vehicles Aerodynamic Drag Reduction Methods

Recent spikes in fuel prices and concern regarding greenhouse gas emissions, automotive design engineers are faced with the immediate task of introducing more efficient aerodynamic designs vehicles. The aerodynamic drags of a road vehicle is responsible for a large part of the vehicle’s fuel consumption and contribute up to 50% of the total vehicle fuel consumption at highway speeds. Review on the research performance of active and passive flow control on the vehicle aerodynamic drag reduction is reported in this paper. This review intends to provide information on the current approaches and their efficiency in reducing pressure drag of ground vehicles. The review mainly focuses on the methods employed to prevent or delay air flow separation at the rear end of vehicle. Researches carried out by a number of researchers with regard to active and passive flow controls method on vehicle and their effect on aerodynamic drag in terms of drag coefficient (CD) was highlighted. Passive methods i.e. Vortex Generator (VG), spoiler and splitter and active flow controls i.e. steady blowing, suction and air jet are among the methods had been reviewed. In addition several attempts to couple these flow control methods were also reviewed. Several aspects of aerodynamic drag that need for further investigation as to assist for vehicles aerodynamic design and for practical reasons were highlighted. Progressive research on active flow control was observed due to its flexibility for wide range of application without body shape modification

Influence Of Process Parameter On The Height Deviation Of Weld Bead In Wire Arc Additive Manufacturing

Significant attention towards Wire and Arc Additive Manufacturing (WAAM) has gradually increased. WAAM technology has been proven in building three-dimensional (3D) metal parts efficiently and economically. The combination of wire and arc welding is promising, especially in depositing metals with higher deposition rate, and low cost of raw materials, as well as manufacturing of a large-scale product. However, there are several process parameters should be optimized to ensure no internal defect, acceptable surface finish and consequently to have a good quality of final parts when using WAAM. Therefore, an experimental design using the Taguchi method was used to determine the effect of welding current, welding voltage, and travel speed on the responses, including the deviation in height were investigated. The results revealed that travel speed was the dominant factor affecting the waviness surface structure on top of the 3D metal parts. Besides, the contribution rate for each factor to the deviation in height was also determined

Surface quality and absorption properties of Polymeric Composite (PLA-PCU) fabricated using 3D printing for articular cartilage application

The objective of this study is to investigate the impact of four 3D printing process parameters (i.e., layer thickness, PCU composition, nozzle speed and extruding temperature) on the surface roughness and absorption rate of the mixture of PolyLactic Acid (PLA) and PolyCarbonate Urethane (PCU). The specimen was printed using a Fused Filament Fabrication (FFF) technology. The response surface methodology was used for analysing all the experimental data and developing an effective empirical prediction model. The results of the study indicated that the generated model was not much significant with regards to absorption rate, while it was very significant for the surface roughness response parameter. A detailed analysis of the results indicated that layer thickness was the most significant factor that affected the surface roughness, while PCU composition affected the absorption rate. The optimal surface roughness (2.5400 µm) and absorption rate (0.0470%) of the printing process parameters was obtained when PCU concentration is 10 wt.%, layer thickness 0.1 mm, nozzle speed 15 mm/s and extruding temperature 195℃

Structure Fabricated using Entry Level 3D Printer / Siti Nur Humaira Mazlan ...[et al.]

3D printing or also known as additive manufacturing (AM) processes fabricate complex mechanical structures by using deposition of the filaments layer by layer technique. AM process has a good capability to fabricate the complex structure compares to conventional machining. However, there is limited design guideline for AM even for the most used AM technique which is fused deposition modeling technique (FDM). Thus, in this paper, various mechanical structures such as overhangs, bridges, wall thickness, hole diameter and vertical wire diameter were fabricated to study the manufacturability of the design structure fabricated by entry level 3D printer using polylactic acid (PLA) material. The parts manufactured were then measured to evaluate the dimensional accuracy and deviations between 3D computer-aided design (CAD) and nominal data. Based on the results, design guidelines for each respective mechanical structure have been recommended

Process Parameter Optimization Of 3D Printer Using Response Surface Method

The purpose of this paper is to minimize the warp deformation that usually occurs to plastic part produced by 3D printers. The process involved 3D solid modelling to design, 3D printing with coated adhesive applied on the printing platform, warping deformation measurement and statistical analysis. The optimization processes involved Design on Experiment (DOE) technique where Responses Surface Methodology (RSM) is applied by using Minitab software. The experiment produced the minimum result of warping deformation value when the layer temperature, infill density, first layer height and other layer height is 192°C, 13%, 0.20mm and 0.30mm respectively

PROTOTYPE DEVELOPMENT OF WIRELESS PNEUMATIC GEAR SHIFTER

Conventional design of transmission gear shifter is basically consists of mechanical linkage of gear lever attached on the side of motorcycle engine with pivot directly connected to the gear shifting mechanism. Shifting up and down of gear positions are performed by moving foot or toe upward and downward on the lever respectively. For disable rider (rider requires special need), shifting gear for manual transmission type of motorcycle with or without clutch system is difficult. In this research, a pneumatic gear shifter is designed and fabricated. It consists of pneumatic circuit with actuator, tanks and air compressor. The movement of gear lever is performed by the pneumatic actuator. Pneumatic tanks are installed to achieve optimum pressure.  It also controlled by wireless system for convenient purpose and buttons installed at the handle. Simple experiment is performed to measure the force for each gear position