Mechanical Design Process Research Articles

Mechanism design optimization through CAD-based Bayesian optimization and quantified constraints

This study addresses the challenge of mechanism design optimization, particularly focusing on the energy efficiency and design space of reciprocating mechanisms. The research question centers on how to effectively utilize Computer-Aided Design (CAD) simulations alongside Bayesian optimization (BO) and a constrained design space to streamline the design optimization process, overcoming the limitations of traditional kinematic and dynamic analysis methods. The objective is to investigate and develop a novel optimization framework that integrates CAD-based simulations with a BO approach. To achieve this, the study employs a methodological approach. At first, the feasibility of a chosen mechanism design is evaluated through a sequence of CAD-motion simulations to quantify the (in)feasibility of this design. When this design appears to be feasible, a CAD-based design evaluation method is started, in which the objective value is extracted by a sequence of CAD-motion simulations. In this paper, we advocate the use of non-parametric Gaussian processes to build a surrogate model of the objective function and the feasible design space constrained by static and dynamic constraints. The main research results demonstrate that the proposed CAD-based Bayesian optimization framework can effectively identify optimal design parameters that minimize the root mean square (RMS) torque while adhering to specified static and dynamic constraints. This optimization approach significantly reduces the complexity associated with analytic methods, making it scalable to more complex mechanisms and implementable by machine builders. In conclusion, the study successfully develops a novel optimization framework that leverages CAD-based simulations and Bayesian optimization to streamline the design process of mechanisms. The results of an emergency ventilator case study with three design parameters show a reduction of the RMS torque with 71% after 255 CAD-based design evaluations. Moreover, the results demonstrate the effectiveness of incorporating constraints into the design optimization process and the usage of Bayesian optimization (BO), providing insights into the obtained optimum. This approach offers probabilistic insights into the expected improvement of the optimum, highlighting that the full optimization potential is utilized in a computationally efficient manner.

A Wearable Fingertip Force Feedback Device System for Object Stiffness Sensing.

Virtual reality technology brings a new experience to human-computer interaction, while wearable force feedback devices can enhance the immersion of users in interaction. This paper proposes a wearable fingertip force feedback device that uses a tendon drive mechanism, with the aim of simulating the stiffness characteristics of objects within virtual scenes. The device adjusts the rotation angle of the torsion spring through a DC motor, and then uses a wire to convert the torque into a feedback force at the user's index fingertips, with an output force of up to 4 N and a force change rate of up to 10 N/s. This paper introduces the mechanical structure and design process of the force feedback device, and conducts a mechanical analysis of the device to select the appropriate components. Physical and psychological experiments are conducted to comprehensively evaluate the device's performance in conveying object stiffness information. The results show that the device can simulate different stiffness characteristics of objects, and users can distinguish objects with different stiffness characteristics well when wearing the force feedback device and interacting with the three-dimensional virtual environments.

Design and experiment of multi-locomotion tensegrity mobile robot

Multi-locomotion tensegrity mobile robots have garnered significant attention in recent research due to their strong terrain adaptability and high stiffness-to-mass ratio. However, the lack of effective design method limits the application range of these robots. In this article, a mechanism design method for the multi-locomotion tensegrity mobile robot is proposed. Firstly, based on the characteristics of worms, mechanism design objectives for the tensegrity robot are put forward from three perspectives, namely bionics, motion law and tensegrity characteristics. Accordingly, the mechanism design process is conducted from two sections in terms of the design of multi-locomotion tensegrity units and the splicing of the identical units. In the mechanism design for the tensegrity units, the rod distribution is firstly determined on compliance with the proposed design objectives, followed by the determination of cable distribution with force-balance analysis method. On this basis, two identical multi-locomotion tensegrity units are axially spliced, and a series of multi-locomotion tensegrity robotic mechanisms can be acquired naturally. Finally, examples are provided, and simulations and experiments are conducted to demonstrate the effectiveness of the proposed mechanism design method.

Design and evaluation of a smart passive dynamic arm support for robotic-assisted laparoscopic surgery

Surgeons performing robotic-assisted laparoscopic surgery experience physical stress and overuse of shoulder muscles due to sub-optimal arm support during surgery. The objective is to present a novel design and prototype of a dynamic arm support for robotic laparoscopic surgery to evaluate its ergonomics and performance on the AdLap-VR simulation training device. The prototype was designed using the mechanical engineering design process: Technical requirements, concept creation, concept selection, 3D-design and built of the prototype. A crossover study was performed on a marble sorting task on the AdLap-VR. The first group performed four trials without the arm support, followed by four trials with the arm support, and the other group executed the sequence vice versa. The performance parameters used were time to complete (s), path length (mm), and the number of collisions. Afterward, the participants filled out a questionnaire on the ergonomic experience regarding both situations. 20 students executed 160 performed trials on the AdLap-VR Significant decreases in the subjective comfort parameters mental demand, physical demand, effort and frustration were observed as a result of introducing the novel arm support. Significant decreases in the objective performance parameters path length and the number of collisions were also observed during the tests. The newly developed dynamic arm support was found to improve comfort and enhance performance through increased stability on the robotic surgery skills simulator AdLap-VR.

Thinking Beyond the Default User: The Impact of Gender, Stereotypes, and Modality on Interpretation of User Needs

Abstract Throughout the mechanical design process, designers, the majority of whom are men, often fail to consider the needs of women, resulting in consequences ranging from inconvenience to increased risk of serious injury or death. Although these biases are well studied in other fields of research, the mechanical design field lacks formal investigation into this phenomenon. In this study, engineering students (n = 301) took a survey in which they read a Persona describing a student makerspace user and a Walkthrough describing the user’s interaction with the makerspace while completing a project. During the Walkthrough, the user encountered various obstacles or Pain Points. Participants were asked to recall and evaluate the Pain Points that the user encountered and then evaluated their perceptions of the makerspace and user. The independent variables under investigation were the gender of the user Persona (woman, gender-neutral, or man), the Walkthrough room case (crafting or woodworking makerspace), and the modality of the Persona and Walkthrough (text- or audio-based). Results showed that participants from the Text-based modality were better able to recall Pain Points compared to participants from the Audio-based modality. Pain Points were assessed as more severe when they impacted women users, potentially stemming from protective paternalism. In addition to finding that the gender of a user impacted the way a task environment was perceived, results confirmed the presence of androcentrism, or “default man” assumptions, in the way designers view end users of unknown gender. Promisingly, providing user Persona information in an audio modality significantly reduced this bias compared to text-based modalities, indicating that providing richer detail in user personas has the capability to reduce gender bias in designers.

3T 31P/1H calf muscle coil for 1H and 31P MRI/MRS integrated with NIRS data acquisition.

Our aim was to design and build a 3T 31P/1H calf coil that is capable of providing both good 31P and 1H transmit and receive performance, as well as being capable of accommodating a near-infrared spectroscopy (NIRS) device for simultaneous NIRS data and MRI/MRS acquisition. In this work, we propose a new 3T 31P/1H birdcage combination design consisting of two co-centrically positioned birdcages on the same surface to maximize transmit efficiency and sensitivity for both nuclei. The 31P birdcage is a high-pass birdcage, whereas the 1H birdcage is a low-pass one to minimize coupling. The diameter of the 31P/1H birdcage combination was designed to be large enough to accommodate a NIRS device for simultaneous NIRS data and MRI/MRS acquisition. The one-layer coil structure of the birdcage combination significantly streamlines the mechanical design and coil assembly process. Full-wave simulation results show that the 31P and 1H are very well decoupled with each other, and the 1H and 31P SNR surpasses that of their standalone counterparts in the central area. Experiment results show that the inclusion of a NIRS device does not significantly affect the performance of the coil, thus enabling simultaneous NIRS and MRI readouts during exercise. Our findings demonstrate the feasibility and effectiveness of this dual-tuned coil design for combined NIRS and MRS measurements, offering potential benefits for studying metabolic and functional changes in the skeletal muscle in vivo.

A New Perspective on Digital Twin-Based Mechanical Design in Industrial Engineering

The advent of digital twin methodologies in industrial engineering is inspiring a transformative wave in mechanical design processes. This innovative framework signifies the convergence of real and virtual worlds, enabling an unprecedented level of synergy between design, simulation, production, and evaluation cycles. The resultant 'digital counterparts' serve as dynamic blueprints that echo the life cycle of their physical kin, unraveling sophisticated opportunities for predictive maintenance, accelerated prototyping, and mitigated risks. Residing at the cusp of this evolution, mechanical design draws immense strategic advantage. The adoption of digital twins unearths potential for holistic design enhancements through real-time condition monitoring, performance prediction, and comprehensive data analytics. These processes structure efficient decision-making protocols, fostering increased product reliability, enhanced operational efficiency, and reduced time-to-market. Moreover, digital twins open new avenues for developing complex systems and large-scale machinery through seamless integration of interdisciplinary skills. Intricate simulations aid in isolating potential hurdles and foreseeing outcomes with substantial accuracy, ensuring a meticulous yet fluid design process. Ultimately, the emergence of digital twins in mechanical design embodies a remarkable shift pivoting towards Industry 4.0, redefining the paradigms of industrial engineering with the blend of cornerstone technologies. Leveraging these state-of-the-art methodologies hints towards an optimistic future regarding sustainable industry practices and technological advancements.

Investigation of Rear Blisk Drum Dynamics Under Consideration of Multi-Stage Coupling

Abstract The analysis of the structural dynamics of multistage cyclic structures as linked components is required to model the interstage coupling. In turbomachinery, this can result in a collaboration between different compressor or turbine stages. This paper investigates the coupling between two rear drum blade integrated disk stages of an axial compressor to support the mechanical design process. Considering the vibration modeshapes of a multistage system, different components may coparticipate in the dynamics. For this reason, criteria to identify the modes affected by the coupling and to quantify this coupling are defined. This allows to distinguish between modes with interstage coupling, requiring the multistage system for their description, and uncoupled modes, involving a single stage. In addition, it is of interest to research methods to reduce the impact of the coupling on the vibrating system without drastically altering the geometry of the components. The vibration analyses of a two-stage compressor generalized geometry, representative of a compressor rear drum blisk, are presented as a study case. The use of a reducing method allows to describe the behavior of the nominal multistage system with a computationally efficient technique, enabling a parametric analysis of the stages' coupling. The investigation considers the effect of a set of geometrical and mechanical parameters on the dynamics, identifying the driving parameters of the coupled vibration characteristics.

Thermal and Mechanical Design of Superheater for Process Industries

The superheater is an important boiler accessory which is widely used in power generation, sugar factories and process industries for ensuring good quality of steam for power generation. This increases the efficiency and life of the turbine blades for thermal power plant. In the research work, pendant type convective superheater is designed for 20 Tonnes/hr for power generation in food processing industry with steam outlet pressure of 45 kg/cm2 and temperature of 450 °C. The superheater was designed considering thermal and mechanical aspects. The process of thermal design involved calculation of overall heat transfer coefficient and surface area for heat transfer. Three-dimensional model of superheater using CATIA V5R20 was created and analysed. The process of mechanical design was used to calculate the working pressure and ensured safe design of superheater.

Optimizing Electrode Configurations for Wearable EEG Seizure Detection Using Machine Learning

Epilepsy, a prevalent neurological disorder, profoundly affects patients’ quality of life due to the unpredictable nature of seizures. The development of a reliable and user-friendly wearable EEG system capable of detecting and predicting seizures has the potential to revolutionize epilepsy care. However, optimizing electrode configurations for such systems, which is crucial for balancing accuracy and practicality, remains to be explored. This study addresses this gap by developing a systematic approach to optimize electrode configurations for a seizure detection machine-learning algorithm. Our approach was applied to an extensive database of prolonged annotated EEG recordings from 158 epilepsy patients. Multiple electrode configurations ranging from one to eighteen were assessed to determine the optimal number of electrodes. Results indicated that the performance was initially maintained as the number of electrodes decreased, but a drop in performance was found to have occurred at around eight electrodes. Subsequently, a comprehensive analysis of all eight-electrode configurations was conducted using a computationally intensive workflow to identify the optimal configurations. This approach can inform the mechanical design process of an EEG system that balances seizure detection accuracy with the ease of use and portability. Additionally, this framework holds potential for optimizing hardware in other machine learning applications. The study presents a significant step towards the development of an efficient wearable EEG system for seizure detection.

Mechanical Design, Planning, and Control for Legged Robots in Distillation Columns

Abstract Dexterous robots have great potential to execute industrial tasks that are not suited to humans. In this work, a novel robotic mobility platform is proposed for use in the chemical industry to enable autonomous distillation column inspection—a tedious and dangerous task for humans. A roller arm mechanism is designed for a quadrupedal robot that enables moving across the distillation column. Required dynamic behaviors are generated with full-body motion planning and low-level control. The holistic process of mechanical design, planning, and control leads to desired behavior, as demonstrated by high-fidelity simulations. This marks a key step toward operating legged robots inside distillation columns.

Biomathematical analysis on mechanical engineering during COVID-19 pandemic

In mechanical engineering research and design process will involve a large number of mathematical applications. In order to analyze the significance and application of mathematics in the research and design of mechanical engineering, this paper lists and analyzes the basic mathematical equations, mathematical models and finite element related problems in some fields of learning. The results show that the application of mathematics in mechanical engineering is not limited to higher mathematics, but also covers the related knowledgeof numerical processing, matrix theory and other coursesduring COVID-19 pandemic.

친환경 바이오연료를 사용하는 난방시스템 디자인설계 및 환경시험평가

Research and development for alternatives to fossil fuels such as coal and petroleum have progressed considerably worldwide. Among clean fuels, bio-diesel has been a representative fuel and it was used for the following advantages; renewable, ready to use with low fine dust emission and non-toxicity. But it is expensive and cause strain on local resources. In our study, to resolve these issues, we developed two types of heating systems by direct input of waste cooking oil, and the heating system was optimized through mechanical design and design process. In addition, we conducted an environmental test to evaluate the reliability and environmental characteristics of the developed device. Firstly, through the design modification of heat recirculation system, more efficient combustion for the complete combustion of bio-fuel(waste cooking oil), was possible. As for the heating system, two products (tube heating system, agricultural hot air blower) were optimized for management convenience, space utilization, and efficiency improvement by 6-step design. From the environmental test result, the combustion efficiency of the heating system was up to 99%, the average oxygen concentration was 8.3%, and the CO concentration was 7.9 ppm for a stable combustion, NOx was up to 67 ppm, and SOx was not detected.

Research on Damage Mechanism and Performance-Based Design Process of Reinforced Concrete Column Members

In order to understand the seismic damage assessment of reinforced concrete column members, the coupling relationship between the capacity degradation and the accumulated hysteretic energy and the displacement history was considered. The energy-based damage index under the random variable amplitude loading history was proposed. On the basis of preliminary research, the corresponding relationship between the damage index and the construction member parameters and seismic parameters was established, the damage mechanism was analyzed according to the damage index, and then the performance-based design process was proposed. It was found that increase in the stirrup ratio can slow down the damage, and the slowing effect was initially fast and then slows. When the reinforcement ratio is doubled, the damage index decreased by 0.063. The longer the earthquake duration was, the more serious the damage was, and this phenomenon was more obvious when the ductility coefficient was larger. With the increase in the ductility coefficient, the damage continuously increased. Therefore, it is an effective way to decrease the damage by controlling the ductility coefficient. Among all the influencing factors, the fundamental period and seismic intensity contributed more significantly to the damage indicators. When the damage index (performance objective) was determined, the target stirrup ratio can be obtained according to the proposed performance design process, that is, this design process can be used in the performance-based design. The design method based on damage index can make up for the deficiency that the design method based on the ductility coefficient does not consider the earthquake duration.

Geometrically-driven generation of mechanical designs through deep convolutional GANs

Despite the freedom Additive Manufacturing (AM) offers when manufacturing organic shapes, it still requires some geometrical criteria to avoid a part's collapse during printing. The most synergetic design approach to AM is Topology Optimization (TO), which finds an optimal free-form given mechanical constraints. However, it is hard for TO to integrate these layout geometry-related constraints and it seldom proposes printable shapes. Therefore, this work leverages the Deep Learning (DL) capability to handle spatial correlations within the mechanical design process by integrating the layout and mechanical constraints at the conceptual level. It proposes a DL-layout-driven solution (DL-TO) trained via a triple-discriminator Generative Adversarial Network (GAN) framework. The DL-TO's performance is demonstrated by generating mechanically valid 2D designs conforming with layout constraints in a fraction of a second. DL-TO's creativity is illustrated by its capability to generate designs with unseen input constraints (passive/active elements) and to propose several shapes for the same input mechanical constraints, a task that is hard for a traditional TO to achieve.

Design of point-type heavy load connection and low impact separation mechanism based on energy flow analysis

In this paper, based on the development of the non-pyrotechnic low impact connection and separation device for heavy load connection of large space vehicles, the design method of connection and separation device is studied. The traditional heavy load connection separation device has a strong loading capacity, but the release of system energy will cause a huge impact during separation. This paper considers the transfer of impact energy in the mechanism design process, reduces separation impact based on energy flow analysis. Based on the analysis of the DOF (Degree of Freedom) constraint function of the separation system and the working requirements of the separation mechanism, the movability model of separation system was established. According to the research on DOF constraints and release, the key of force constraints in DOF constraints of the separation mechanism is obtained, and the separation mechanism that can implement the force constraints and release is analyzed. Furthermore, based on the energy flow analysis of the separation mechanism, the design method of the low impact separation mechanism is proposed, obtained a non-self-locking thread pair connection separation mechanism. The effectiveness of the design method was verified by the energy conversion analysis of the separation mechanism.

An approach for the optical and mechanical design of an X-ray beamline: application to the plane-wave CDI station CATERETÊ/SIRIUS

Experiments involving nano-focusing or coherence applications require positional stability of a few nanometers and angular stability of tens of nanoradians for all critical optical components along the beamline (in the range of 1 Hz up to 2.5 kHz). Several optical components based on high-precision mechatronics principles with optimized dynamics to cope with those stability requirements have been recently designed and developed at LNLS. An approach combining optical and mechanical design methodologies and processes was applied to new beamline projects. The process starts with optical design using ray-tracing and wave propagation simulations aiming for the specified beam parameters. In a second step, alignment tolerances and stability issues are addressed in the mechanical design of each component. If those requirements cannot be reached in the predictive models based on the available technologies, size and shape of the optics itself or the optical scheme may be redefined restarting the optical simulation. This work applies this beamline design process to the CATERETÊ beamline, which allows for plane-wave CDI experiments. Using side-bounce deflecting cylindrical mirrors and a four-crystal monochromator, a focused beam size of ~ 40 x 30 μm2 (at 9 keV) with a depth-of-focus of 12 m (plane-wave) and high degree of coherence is obtained. We review key aspects of the optical and mechanical designs. In addition, we further extend the modelling process to enable systematic commissioning support by simulating beam parameters on diagnostic elements located downstream each optical element.

Biomathematical Analysis on Mechanical Engineering during COVID-19 Pandemic

In mechanical engineering research and design process will involve a large number of mathematical applications. In order to analyze the significance and application of mathematics in the research and design of mechanical engineering, this paper lists and analyzes the basic mathematical equations, mathematical models and finite element related problems in some fields of learning. The results show that the application of mathematics in mechanical engineering is not limited to higher mathematics, but also covers the related knowledge of numerical processing, matrix theory and other courses during COVID-19 pandemic.

Hybrid Teaching for 3D Printing Skill Training and Critical Forming Parts Design

3D printing capability involved with machine operation and maintaining, critical motion mechanical design and key process parts for fused plastic deposition. For high vocational skill training in the polytechnic institution, ensure the students fulfil the goal of talent training for major programs, and reflects the integration of core courses teaching and new technology innovation applications. Through the hybrid teaching and training, students perform the equipment operation, three-dimensional design and process related parts innovation, combined with hands operation and brain thinking, which melton morality and skills. They exercise the craftsmanship spirit of excellence and innovation, and provide useful experience for the development of relevant vocational skills of future advanced manufacturing technical workers.

Application of the quality function deployment method in the mechanical structure design of subsea power devices

Mechanical structure design is the most important process in the research and development of undersea equipment. Traditional design methods have limitations in obtaining functional demand information, determining the design direction, focusing on technical resources, guaranteeing systematic quality, etc. These limitations often reflect many problems, such as low design efficiency, waste of resources, and weak reliability of the finished products. By integrating the idea of grasping “the beginning” and “the end” into the process of mechanical design, this paper introduced a method called quality function deployment (QFD) and applied it to the mechanical design of subsea power devices to demonstrate and verify a robust design process with a clear direction and focused application of resources. Combined with the example of the mechanical design for the subsea power device, QFD was applied to analyse functional technical elements by establishing the house of quality (HoQ) models. And then, it was achieved a stable deployment and realization of the structural function for the subsea power device. Furthermore, for the key purpose of ensuring adequate structural strength and watertight reliability, this study selected suitable material, designed reasonable structures, and integrated finite element analysis technology to carry out mechanical simulations. Finally, the design of the mechanical structure for the subsea power device was robustly implemented.