Mechanical Structure Research Articles

Influence of drilling incidence angle on the drilling force distribution of pneumatic impactor

Pneumatic impactor is widely used in the drilling process of various medium and high hard rocks with poor drill ability. Currently, there is relatively little analysis on the impact of the inclination of the rock surface during the drilling process on the drilling efficiency and excavation capability of pneumatic impactors. Based on the dynamic theory of impact drilling and finite element method (FEM), the constitutive model of HJC criterion and INVENTOR 3D mechanical structure design software, a 3D numerical analysis system of piston-bit head-rock during pneumatic impactor drilling is established by ANSYS LS-DYNA, a nonlinear dynamic analysis software. The numerical results of drilling force at different incidence angles are analyzed in detail. For the rock without initial hole, the ratio of maximum to minimum drilling force under the conditions of considering incidence angle δ, only considering incidence angle β and considering both β and δ is 3.114, 3.161 and 3.873, respectively. For the rocks with initial holes, the ratio of maximum to minimum drilling force under the same and different incidence angles is 1.810 and 2.090, respectively. Through nonlinear fitting for numerical results, the corresponding fitting solution is obtained, and the relative error between fitting solution and numerical solution is analyzed to be between 11.72%~15.58%, which can meet the requirements of engineering application. The analysis results provide references for the mechanical structural optimization design and use of pneumatic impactor.

Smart Mechanical Structures and Design for Advanced Adhesives: A Review

Abstract Smart adhesives with engineered mechanical structures have emerged as a transformative technology with broad applications in fields such as wearable healthcare devices, bioengineering, and soft robotics. By integrating advanced mechanical architectures like kirigami, tessellations, and multilayered designs, these adhesives exhibit enhanced surface and mechanical properties that lead to superior interfacial adhesion. Such designs offer critical advantages—improved stretchability, substrate conformability, and increased adhesion strength—over conventional adhesives. This review explores the range of engineered structures used in smart adhesives and demonstrates how these innovations address the limitations of traditional adhesives. Additionally, we discuss their applications in wearable healthcare devices, flexible electronics, and robotics.

The Application Analysis of Sequential Circuit in the Design of Multifunctional Clock

As time management is getting harder in this fast pace of life, traditional clocks have encountered many problems for its complexity and simple functions because it can also be a problem to integrate multiple capabilities into one device based on mechanical inner structure. Therefore, digital clocks can be a better choice and this experiment intended to provide a way of designing the circuit of a multifunctional digital clock based on components used in sequential circuits. Within the circuit, counter, reversible counter and comparator were applied to realize counting, time-setting, countdown, alarming and on-time alarm functions. In this article, the working principles of main chips and the key designing methods will be introduced. NI Multisim was applied to provide simulated results of the behavior of this clock. The results turned out to meet all expectations even though the experiment had inevitable limitations. Thus, it is suggested that further researches can be conducted to ensure a more energy-efficient and precise clock with more advanced useful capabilities.

Mechanical Design and System Construction of Ankle Rehabilitation Robots

The ankle joint is the most heavily loaded joint in the human body and plays a crucial role in daily activities, making it susceptible to injuries. Currently, rehabilitation robots for the ankle joint facilitate the assessment of rehabilitation outcomes and the adjustment of rehabilitation programs, demonstrating significant practical value and application prospects. This paper reviews the mechanical structure design and control system construction of existing ankle rehabilitation robots. In this narrow review, we first analyze the characteristics and issues of current mechanical designs of ankle rehabilitation robots based on the analysis of physiological structure of the ankle joint. Subsequently, we examine design aspects aimed at enhancing precision based on the movement characteristics of the ankle joint, suggesting directions for further research. The control system is categorized into three types based on the driving method: passive, active, and assistive, with an explanation of their mechanisms of action. Finally, we summarize our findings and propose perspectives about the future development of ankle rehabilitation robots

Neutralizing antibody landscape of the non-polio Enteroviruses and future strategy

The non-polio Enteroviruses (NPEVs), consist of enteroviruses, coxsackieviruses, echoviruses, and rhinoviruses, are causative agents for a wide variety of diseases, ranging from common cold to encephalitis and acute flaccid paralysis (AFP). In recent years, several NPEVs have become serious public health threats, include EV-A71, which has caused epidemics of hand-foot-and-mouth disease (HMFD) in Southeast Asia, and EV-D68, which caused outbreaks of severe respiratory disease in children worldwide. Infections with these viruses are associated with neurological diseases like aseptic meningitis and AFP. Currently, apart from inactivated EV-A71 vaccines that were developed in China, no effective measures are available to prevent or treat NPEV infections. Antibody-mediated immunity is crucial for preventing and limiting viral infections, and potent neutralizing antibodies could serve as potential therapeutic agents. In this review, we describe recent progress in the NPEVs neutralization antibodies, summarizing the characteristics, breadth, and potency against NPEVs, such as EV-A71, CVA16, EV-D68, and echovirus. We focus on not only through the study of viral epitopes but also through the understanding of virus-antibody interactions. Also, we decipher the role of antibodies in the attachment of the virus to receptors, internalization, and uncoating process, providing insight into virus neutralization mechanisms. Moreover, bi-specific antibodies or multivalent antibodies with better potency are also discussed. Therefore, an in-depth understanding of structures of enterovirus and mechanisms of antibody neutralization should be useful for future strategies in guiding the design of a rational antiviral agent against NPEVs infections.

Dynamic Task Planning for Multi-Arm Harvesting Robots Under Multiple Constraints Using Deep Reinforcement Learning

Global fruit production costs are increasing amid intensified labor shortages, driving heightened interest in robotic harvesting technologies. Although multi-arm coordination in harvesting robots is considered a highly promising solution to this issue, it introduces technical challenges in achieving effective coordination. These challenges include mutual interference among multi-arm mechanical structures, task allocation across multiple arms, and dynamic operating conditions. This imposes higher demands on task coordination for multi-arm harvesting robots, requiring collision-free collaboration, optimization of task sequences, and dynamic re-planning. In this work, we propose a framework that models the task planning problem of multi-arm operation as a Markov game. First, considering multi-arm cooperative movement and picking sequence optimization, we employ a two-agent Markov game framework to model the multi-arm harvesting robot task planning problem. Second, we introduce a self-attention mechanism and a centralized training and execution strategy in the design and training of our deep reinforcement learning (DRL) model, thereby enhancing the model’s adaptability in dynamic and uncertain environments and improving decision accuracy. Finally, we conduct extensive numerical simulations in static environments; when the harvesting targets are set to 25 and 50, the execution time is reduced by 10.7% and 3.1%, respectively, compared to traditional methods. Additionally, in dynamic environments, both operational efficiency and robustness are superior to traditional approaches. The results underscore the potential of our approach to revolutionize multi-arm harvesting robotics by providing a more adaptive and efficient task planning solution. We will research improving the positioning accuracy of fruits in the future, which will make it possible to apply this framework to real robots.

Damage location in mechanical structures by multi-objective pattern search

Damage location in mechanical structures by multi-objective pattern search

First-Principles Study on the Mechanical Properties of Ni3Sn4-Based Intermetallic Compounds with Ce Doping

Ni3Sn4 intermetallic compound (IMC) is a critical material in modern electronic packaging and soldering technology. Although Ni3Sn4 enhances the strength of solder joints, its brittleness and anisotropy make it prone to crack formation under mechanical stress, such as thermal cycling or vibration. To improve the plasticity of Ni3Sn4 and mitigate its anisotropy, this study employs first-principles calculations to investigate the mechanical properties and electronic structure of the doped compounds Cex Ni3−xSn4 (x = 0, 0.5, 1, 1.5, 2) by adding the rare earth element Ce. The results indicate that the structure Ce0.5 Ni2.5Sn4 has a lower formation enthalpy (Hf) compared to other doped structures, suggesting enhanced stability. It was found that all structures exhibit improved plasticity with Ce doping, while the Ce0.5 Ni2.5Sn4 structure shows relatively minor changes in hardness (H) and elastic modulus, along with the lowest anisotropy value (AU). Analysis of the total density of states (TDOS) and partial density of states (PDOS) reveals that the electronic properties are primarily influenced by the Ni-d and Ce-f orbitals. At the Fermi level, all Cex Ni3−xSn4 (x = 0, 0.5, 1, 1.5, 2) structures exhibit metallic characteristics and distinct electrical conductivity. Notably, the TDOS value at the Fermi level for Ce0.5 Ni2.5Sn4 lies between those of Ni3Sn4 and other doped structures, indicating good metallicity and conductivity, as well as relative stability. Further PDOS analysis suggests that Ce doping enhances the plasticity of Ni3Sn4. This study provides valuable insights for the further application of rare earth elements in electronic packaging materials.

An Improved Multi-point Chord Reference Measurement Device and Error Correction Method for Corrugation Measuring in Sharp Curves

Background: The traditional chord reference method and its device have faced challenges matching the sharp curve track. Thus, it is of utmost importance to research and develop a measurement device and method that can obtain accurate and comprehensive information regarding rail running band corrugation. Aims: It provides a solution for the measurement of the multi-point chord reference method on sharply curved rails and, at the same time, meets the demand for data richness and accuracy in theoretical studies on the causes of rail corrugation and wheel-rail contact relationships. Objective: This paper aims to research and design a measurement device based on the multi-point chord reference method for the rail running band corrugation. Meanwhile, the error in measuring the sharp curve rail is corrected and verified by simulation. Methods: The lateral information of rail running band is obtained by using a line laser profile sensor; the rail corrugation measurement model and error correction model of the rail running band area are established based on multi-point reference system; the simulation of the system model is carried out using Matlab; and the mechanical structure is built for static testing. Results: The measurement model based on the profile sensor and multi-point chord reference system can accurately obtain the rail corrugation waveform of any longitudinal measurement line in the running band area. The measurement results can be accurately corrected for a radius of 200m- 400m, the error parameters can be effectively improved, and the mechanical mechanism of the measurement system runs stably. Conclusion: The results show that the measurement model can accurately measure the rail corrugation of the sharp curve section, and the multi-waveform in the rail running band area has good measurement performance, but the mechanical structure can be optimized and improved in the light weight.

Omics based technology application in poultry meat research.

Omics techniques, including genomics, transcriptomics, proteomics, metabolomics, and lipidomics, analyze entire sets of biological molecules to seek comprehensive knowledge on a particular phenotype. These approaches have been extensively utilized to identify both biomarkers and biological mechanisms for various physiological conditions in livestock and poultry. The purpose of this symposium was not only to focus on how recent omics technologies can be used to gather, integrate, and interpret data produced by various methodologies in poultry research, but also to highlight how omics and bioinformatics have increased our understanding of poultry meat quality problems and other complex traits. This Poultry Science Association symposium paper includes 5 sections that cover: 1) functional annotation of cis-regulatory elements in the genome informs genetic control of complex traits in poultry, 2) mass spectrometry for proteomics, metabolomics, and lipidomics, 3) proteomic approaches to investigate meat quality, 4) spatial transcriptomics and metabolomics studies of wooden breast disease, and 5) multiomics analyses on chicken meat quality and spaghetti meat. These topics provide insights into the molecular components that contribute to the structure, function, and dynamics of the underlying mechanisms influencing meat quality traits, including chicken breast myopathies. This information will ultimately contribute to improving the quality and composition of poultry products.

Structure failure and strength evaluation of honeycomb-based sandwich composites under variable hydro-thermal-mechanical load

The high-strength and lightweight sandwich structures have broad application prospect in aerospace, wind turbine generator, traffic and civil engineering. The sandwich structures usually service with severe environment and complicated mechanical load, structure failure and strength prediction are crucial issues. Under time-varying and optional position hydro-thermal–mechanical loading, this paper systematically analyzes strength failure, buckling and delamination of a sandwich beam with carbon fiber-reinforced polymer face sheet and aluminum honeycomb core. Effects of elastic boundary conditions, hydrothermal stress, configuration of honeycomb cell and thickness of face sheet on failure pattern and critical failure loading are evaluated. The theoretical deformation model is verified by performing a bending experiment of cantilever beam. For the honeycomb core with small re-entrant angle and shot horizontal cell wall, the sandwich cantilever beam occurs strength failure of face sheet and delamination is happened in simply supported beam. With increase of re-entrant angle and cell wall length, buckling of horizontal cell wall becomes the primary failure pattern of sandwich beam. With thickness increase of face sheet, the failure pattern switches from face sheet’s strength failure to delamination. The critical load for delamination decreases to a volley value and then increases with thickness of face sheet.

Enhanced Pb immobilization by CaO/MgO-modified soybean residue (okara) in phosphate mining wasteland soil: Mechanism and microbial community structure.

Lead (Pb) contamination is an inevitable consequence of phosphate mining, necessitating the development of effective remediation strategies. This study investigated the use of CaO/MgO-modified okara (CMS) as an eco-friendly approach to remediate Pb-contaminated soils from phosphate mining wastelands. In the present study, following 30d of CMS application, the exchangeable Pb content was significantly decreased to 10.46%, with the majority of Pb transforming into more stable forms: carbonate-bound Pb (56.44%), Fe/Mn oxide-bound Pb (11.03%), and organic-bound Pb (19.58%). Additionally, the treatment led to a substantial enhancement in total phosphorus, available phosphorus, ammonium, and soil organic matter, thereby improving soil fertility. The microbial community structure was also significantly influenced by CMS, with a notable increase in Firmicutes to 45%. Key genera within the microbial community included Azospirillum, Pseudoxanthomonas, Sphingomonas, and Microvirga, with Pseudoxanthomonas and Massilia being the main differential species. These genera were significantly positively correlated, contributing to the maintenance of microbial community homeostasis and promoting the production of CO32- and PO43-, which further accelerated Pb immobilization. The results indicate that CMS is an effective amendment for Pb immobilization in contaminated soils, enhancing soil fertility and modulating the microbial community to promote Pb stabilization. This provides valuable insights into the ecological remediation of Pb-contaminated soils and water bodies, highlighting the potential of waste reuse in environmental management.

Design and Development of a Four-Wheeled Mobile Robot (WMR) for Any Terrain

This paper presents the design, development, and analysis of an all-terrain Wheeled Mobile Robot (WMR). A Wheeled Mobile Robot (WMR) is an autonomous robot that uses wheels for locomotion, allowing it to move efficiently on flat surfaces. These robots are commonly used in various applications, from industrial automation to service robots and research platforms. The robot aims to achieve high mobility on diverse terrains, remote teleoperation, and an effective payload handling capability. The research includes the design and implementation of the mechanical structure, electronic components, control systems, and robot performance analysis. Special focus is given to the kinematic behavior, vibration analysis, and simulation of various components. The robot can carry loads up to 5 kg and navigate complex terrains, including stair climbing. The methodology followed includes structure design, integration of electronic components, assembly, and subsequent trials and simulations. The results demonstrate the robot's potential for practical applications in diverse fields such as exploration, rescue operations, and industrial automation. In summary, wheeled mobile robots are versatile, efficient, and widely used in various industries. Their design carefully balances mechanical, electronic, and software components to achieve reliable and autonomous operation. As technology advances, WMRs become more capable and adaptable, expanding their range of applications.

Image detection method for multi-category lesions in wireless capsule endoscopy based on deep learning models.

Wireless capsule endoscopy (WCE) has become an important noninvasive and portable tool for diagnosing digestive tract diseases and has been propelled by advancements in medical imaging technology. However, the complexity of the digestive tract structure, and the diversity of lesion types, results in different sites and types of lesions distinctly appearing in the images, posing a challenge for the accurate identification of digestive tract diseases. To propose a deep learning-based lesion detection model to automatically identify and accurately label digestive tract lesions, thereby improving the diagnostic efficiency of doctors, and creating significant clinical application value. In this paper, we propose a neural network model, WCE_Detection, for the accurate detection and classification of 23 classes of digestive tract lesion images. First, since multicategory lesion images exhibit various shapes and scales, a multidetection head strategy is adopted in the object detection network to increase the model's robustness for multiscale lesion detection. Moreover, a bidirectional feature pyramid network (BiFPN) is introduced, which effectively fuses shallow semantic features by adding skip connections, significantly reducing the detection error rate. On the basis of the above, we utilize the Swin Transformer with its unique self-attention mechanism and hierarchical structure in conjunction with the BiFPN feature fusion technique to enhance the feature representation of multicategory lesion images. The model constructed in this study achieved an mAP50 of 91.5% for detecting 23 lesions. More than eleven single-category lesions achieved an mAP50 of over 99.4%, and more than twenty lesions had an mAP50 value of over 80%. These results indicate that the model outperforms other state-of-the-art models in the end-to-end integrated detection of human digestive tract lesion images. The deep learning-based object detection network detects multiple digestive tract lesions in WCE images with high accuracy, improving the diagnostic efficiency of doctors, and demonstrating significant clinical application value.

Wrist Exoskeleton Device with a Novel Cable Drive Solution

This paper presents the design of a lower limb exoskeleton made for the purpose of wrist joint rehabilitation. The authors use the exoskeleton structure in order to cope with the user’s upper-limb kinematics and to provide motion to the wrist joint when the arm is in any possible spatial configuration. To reduce the inertia of the mechanical structure, the motors are fixed at the back of the user and the power transmission is realized via a cable drive transmission. Two elastic cables are used to control the flexion/extension movement of the wrist joint. The tensions inside the elastic cables are controlled within the use of 2 torque sensors. By using two DC motors, the actuation unit can act like human tendons and provides more natural assistance motion. At the output axis, a third torque sensor is used to allow the control of the interaction between the mechanism and the user’s wrist joint.

Lignin charcoal/preparation of chitosan composite membrane and H2S adsorption properties

Abstract In this study, chitosan was first used as the raw material for filmmaking, and the film-forming conditions were optimized to prepare six kinds of chitosan-based membranes, and then charcoal composite membrane materials were prepared by adding different amounts of lignin charcoal to fill in the base membranes; the adsorption performance of the composite membrane was analyzed using H2S as the target, and the mechanical properties and structure of the composite membrane were explored using various testing techniques. The experimental results showed that the chitosan-based membrane could adsorb a certain amount of H2S due to its hydroxyl-rich surface. When lignin carbon was added to it, and with the increase of the content of lignin carbon, the performance of the membrane adsorption of H2S was improved, but the mechanical properties decreased, and in a comprehensive comparison of the adsorption performance and mechanical properties of the composite membrane, which had a better adsorption length of H2S adsorption of 84 min and the tensile strength of 1.65 MPa. The pore structure in the composite membrane due to microphase separation and the exposure of oxygen-containing functional groups on the surface of the base membrane and charcoal were the main reasons for the effective retention of H2S.

Research on the Application of ANSYS in the Optimization and Lightweight of Mechanical Structures

Research on the Application of ANSYS in the Optimization and Lightweight of Mechanical Structures

STRUCTURAL AND FUNCTIONAL PROTOTYPING OF THE EXECUTIVE PART OF THE ANGULAR MANIPULATOR ROBOT

In today's conditions of total digitization and informatization of all spheres of activity, more and more agro-industrial enterprises direct their resources to the development and implementation of modern technical and technological solutions, to modernize their own production capacities, with the prospect of ensuring competitiveness on domestic and foreign markets. In turn, such technological renewal of the agricultural sector of the economy is usually based on the use of high-tech systems of management, monitoring, control, management and automation of production processes, with the use of highly integrated SMART systems and the involvement of artificial intelligence technologies. Taking into account the significant volumes of cargo processing, agricultural enterprises, in particular in warehouses, a promising direction and reserve for ensuring high labor productivity is the use of robotic manipulators, and research is devoted to increasing their functionality and maneuverability, including through the use of intelligent control systems and optimization of the structure of executive mechanisms. relevant and will have practical value. The article substantiates the conditions for ensuring functional and structural similarity and proposes criterion equations of similarity for a large-scale transition from a natural sample of an industrial manipulator to a physical model-prototype. On the basis of the obtained criteria and using the scaling factors, the design parameters of the prototype were determined, a computer 3D model was developed, and based on the analysis of the trajectories, corrections were made to the linear dimensions of the manipulator and the ranges of angular movements of the links, as well as the compliance of the created prototype with the conditions of physical modeling was checked, according to the criteria of similarity. Also, the article presents the process of manufacturing an angular manipulator by using additive technologies of layer-by-layer build-up of parts on a 3D printer.

Synchronization of the vibration system driven by four eccentric rotors with perpendicular and coplanar axes

This paper proposes a vibration mechanical structure capable of achieving two synchronous motion states. Its distinctive feature lies in utilizing four eccentric rotors (ERs) with coplanar and perpendicular axes as the excitation source. By modeling this vibration system and conducting theoretical analysis, the synchronous condition and its stability for achieving synchronous motion among four ERs are obtained. Based on theoretical results, the dynamic characteristics, coupling torques, synchronous capability coefficients and phase differences of ERs are discussed numerically. According to the stable phase difference, the variation of the excitation resultant force from four ERs is also investigated. Finally, experiments valid the system has two synchronous states. In pre-resonance, four ERs are in-phase resulting in the linear motion of the vibrating body. However, in post-resonance, ERs along the parallel axes are in-phase, while ERs along the perpendicular axes are in anti-phase. Hence, the body remains stationary because excitation forces cancel each other out. In summary, these conclusions provide a theoretical basis for the structural design of vibratory machinery.

A Comprehensive Review of Control Challenges and Methods in End-Effector Upper-Limb Rehabilitation Robots

In the last decades, there has been an increasing number of human patients who suffer from upper-limb disorders limiting their motor abilities. One of the possible solutions that gained extensive research interest is the development of robot-aided rehabilitation training setups, including either end-effector or exoskeleton robots, which showed various advantages compared to traditional manual rehabilitation therapy. One of the main challenges of these systems is to control the robot’s motion to track a desirable rehabilitation training trajectory while being affected by either voluntary or involuntary human forces depending on the patient’s recovery state. Several previous studies have been targeting exoskeleton robotic systems focusing on their structure, clinical features, and control methods, with limited review on end-effector-based robotic rehabilitation systems. In this regard, an overview of the most common end-effector robotic devices used for upper-limb rehabilitation is provided in this paper, describing their mechanical structure, features, clinical application, commercialization, advantages, and shortcomings. Additionally, a comprehensive review on possible control methods applied to end-effector rehabilitation exploitation is presented. These control methods are categorized as conventional, robust, intelligent, and most importantly, adaptive controllers implemented to serve for diverse rehabilitation control modes, addressing their development, implementation, findings, and possible drawbacks.