Abstract: This paper deals with reasoning about designs using frequent pattern mining methods. It also describes a prototype system supporting design and reasoning, where graph theory is applied to the computational process. Searching a large database of solutions for frequently occurring patterns allows us both to retrieve solutions of similar design tasks and to evaluate newly created innovative solutions.
Abstract: That wheelchair user’s shoulder joint injuries are directly related to poor wheelchair design and the location of the wheelchair driving mechanism has been proven clinically. This work presents a novel approach to rapidly customize the design of manual wheelchairs, such that each user can easily obtain a custom manual wheelchair, thereby reducing the potential for shoulder joint injury. In this study, a human-chair system composed of a human body and a wheelchair was simulated as a plain single-loop five-bar linkage. Mobility analysis was conducted to identify the corresponding joint workspace. By analyzing linkage movement and the upper-limb muscle strength of a user, the optimal location of the wheel hub and optimal radius of the handwheel were identified as the bases of a customized design for manual wheelchairs.
Abstract: The solderability and reliability of SnAgCu and SnAgCuSbBiNi lead-free solders were assessed against SnPbAg solder on a range of PCB finishes. A novel solderability test has been developed to assess the solder system’s ability to realign when a deliberately inaccurate solder stencil printing process was applied. This has shown to be an excellent way to compare PCB finishes and solders, as well as define process parameters. Electroless Nickel Immersion Gold (ENIG) finish proved to give the best solderability and the optimum process parameters were also found. SnPbAg solder has shown superior thermal cycling performance compared to SnAgCu.
Abstract: Bicycle design largely contradicts human motion, necessitating consideration of both the bicycle structure and the kinematic efficiency in the dimensions of the rider’s limbs, as well as human factor engineering, i.e. comfortability. By focusing on the kinematic model of 5-bar linkage and joints workspace, this study examines the most appropriate bicycle design and the riding posture to ensure that muscles can produce the effective moment and increase driving efficiency of a crank necessary. For upright, racing and recumbent bicycle types, assumptions are made regarding mobility analysis and the system of man-machine systems of bicycles estimated as well. Simulation results can identify the major dimensions of bicycle designing for different riders efficiently by inputting physical measurements of the rider and the angle range of driving force, subsequently increasing the riding efficiency to decrease the load of lower limbs of riders and satisfying ergonomic requirements of bicycle riders.
Abstract: A novel touch-trigger probe system is proposed in this paper. The probe houses the stylus shaft on a special diaphragm spring that is exclusively designed with the utilization of Finite Element Analysis (FEA). In the probe system, Giant Magneto-Resistive (GMR) sensors are employed to measure the motion of the stylus shaft in the principal directions. The proposed (and implemented) probe is tested on a three-axis CNC electrical discharge machine (EDM) and the results acquired from those experiments are discussed. The preliminary work presented in this paper demonstrates the capabilities of GMR based probing technology in dimensional metrology.
Abstract: The paper analyzes aspects regarding the product development process of a complex product containing sub-assemblies. The sub-assembly is considered as an independent product integrated in a general assembly. The paper proposes new ideas, adding to the state of art in this field. Thus, a proposed scheme of the product development process is applied with new considerations in the case of a complex product containing sub-assemblies. This scheme contains distinct stages for the main developer, aiming with the general coordination and even the development of sub-assemblies, and third-parties, which develop other sub-assemblies (whether manufactured or not by the main developer).
Abstract: In this research, patent maps were first drawn by searching, organizing and classifying those patents related to bicycles’ capabilities and technologies, and the direction of improving and inventing folding bicycles was found out with the patent maps. Next, the methodology of TRIZ was applied to analyze the problems; the basic technological contradictions were confronted, and the resolve program was developed. In the end, an improved folding bicycle was designed, using PRO/E, the drawing software, to complete the product’s blueprint.
Abstract: . Deployable truss has a wide range application in aerospace industry. Two important issues in the design of all deployable space structures are the weight and its stiffness in the deployed state. This is because lower weight of deployable truss can greatly save the cost of launching and higher stiffness can improve the loading capacity. This paper aims to design a tapered deployable mast with lower weight and higher stiffness. The mobility analysis and geometry condition is first introduced. Then structural optimization problem with mass as its objective is solved by using ANSYS Parametric Design Language (APDL). The optimal results show the proposed tapered mast has excellent performance on mechanical properties by comparing with normal mast with identical cross section. Finally, some possible applications and problems are described.
Abstract: To improve accuracy in the engineering design of hydraulic dampers, a dynamic mathematic model for its working fluid density, viscosity, modulus and stiffness is established. The dynamic flow loss due to volumetric change and pressure leakage is also formulated, wherein the dynamic back pressure in the air chamber is coupled. Simulation results show that most of the fluid properties change obviously when the damper is subjected to external excitations, they are not constant values. The viscosity would drop 74.68% and the flow loss would soar 298.68% with the increase of fluid temperature; the modulus and the stiffness would also drop over 20% when the entrapped air ratio increases, but the density is relatively robust to both variations. The established mathematic model gives a dynamic representation of the fluid property under real service conditions, it has already been applied to the engineering design of several hydraulic damper products in industry, and the effectiveness is validated by pertinent product experiments.