Pub Date : 2025-03-15DOI: 10.1016/j.mechmachtheory.2025.105991
Cheng-Hsuan Hsu, Chi-Shiun Jhuang, Dar-Zen Chen
This paper presents a slider-crank spring gravity balance module for a rotary link and its application to serial manipulators. The spring is arranged in a slider-crank mechanism, its elastic energy is a quadratic function of the crank angle. The gravitational energy of a rotary link can be expressed as a quadratic function of half the link angle. It shows energies matched when the crank angle is half the link angle with a phase difference and the spring stiffness is a function of the link mass. Thus, the balance module is formed. In a serial manipulator, the gravitational energy of a remote link is expressed as the sum of quadratic functions of the angle of itself and preceding links. It can be matched by the elastic energy of the modules on the link itself and the preceding links respectively. Thus, the balance module can be applied to serial manipulators. Torque measurement tests for balancing a rotary link and a 2-DOF serial manipulator by balance modules are performed and show the driving torques are reduced by over 90 % by the balance module.
{"title":"A novel slider-crank spring gravity balance module for 1-DOF rotary link and its application to serial manipulators","authors":"Cheng-Hsuan Hsu, Chi-Shiun Jhuang, Dar-Zen Chen","doi":"10.1016/j.mechmachtheory.2025.105991","DOIUrl":"10.1016/j.mechmachtheory.2025.105991","url":null,"abstract":"<div><div>This paper presents a slider-crank spring gravity balance module for a rotary link and its application to serial manipulators. The spring is arranged in a slider-crank mechanism, its elastic energy is a quadratic function of the crank angle. The gravitational energy of a rotary link can be expressed as a quadratic function of half the link angle. It shows energies matched when the crank angle is half the link angle with a phase difference and the spring stiffness is a function of the link mass. Thus, the balance module is formed. In a serial manipulator, the gravitational energy of a remote link is expressed as the sum of quadratic functions of the angle of itself and preceding links. It can be matched by the elastic energy of the modules on the link itself and the preceding links respectively. Thus, the balance module can be applied to serial manipulators. Torque measurement tests for balancing a rotary link and a 2-DOF serial manipulator by balance modules are performed and show the driving torques are reduced by over 90 % by the balance module.</div></div>","PeriodicalId":49845,"journal":{"name":"Mechanism and Machine Theory","volume":"209 ","pages":"Article 105991"},"PeriodicalIF":4.5,"publicationDate":"2025-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143628079","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-11DOI: 10.1016/j.mechmachtheory.2025.105970
Eduardo Henrique de Paula, Helio Fiori de Castro
This research presented a dynamic model of a planetary geared rotor system and investigated the influence of tooth root cracks on the system’s response. The rotor components were modeled using the finite element method, while the planetary gearbox members were modeled with the lumped parameter method. The model assumed a non-rotating planetary carrier and planet gears equally spaced. Different parameters were considered for cracks at the tooth root of the ring, sun, and first planet gears. The system’s response was analyzed by comparing the frequency domain acceleration response, the acceleration signal’s power spectrum, and the intrinsic mode functions obtained via empirical mode decomposition of the acceleration signal for the healthy and cracked system. Results indicated that crack size is the most significant parameter in altering the system’s response. The signal’s power spectrum enabled clear crack detection, size differentiation, and identification of the affected gear. The empirical mode decomposition of the acceleration signal proved to be particularly advantageous in distinguishing between crack sizes in higher frequency ranges, with the first intrinsic mode function showing significant differences depending on the crack size.
{"title":"Effect of gear tooth root crack on the dynamic response of a planetary geared rotor system","authors":"Eduardo Henrique de Paula, Helio Fiori de Castro","doi":"10.1016/j.mechmachtheory.2025.105970","DOIUrl":"10.1016/j.mechmachtheory.2025.105970","url":null,"abstract":"<div><div>This research presented a dynamic model of a planetary geared rotor system and investigated the influence of tooth root cracks on the system’s response. The rotor components were modeled using the finite element method, while the planetary gearbox members were modeled with the lumped parameter method. The model assumed a non-rotating planetary carrier and planet gears equally spaced. Different parameters were considered for cracks at the tooth root of the ring, sun, and first planet gears. The system’s response was analyzed by comparing the frequency domain acceleration response, the acceleration signal’s power spectrum, and the intrinsic mode functions obtained via empirical mode decomposition of the acceleration signal for the healthy and cracked system. Results indicated that crack size is the most significant parameter in altering the system’s response. The signal’s power spectrum enabled clear crack detection, size differentiation, and identification of the affected gear. The empirical mode decomposition of the acceleration signal proved to be particularly advantageous in distinguishing between crack sizes in higher frequency ranges, with the first intrinsic mode function showing significant differences depending on the crack size.</div></div>","PeriodicalId":49845,"journal":{"name":"Mechanism and Machine Theory","volume":"209 ","pages":"Article 105970"},"PeriodicalIF":4.5,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143591621","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-11DOI: 10.1016/j.mechmachtheory.2025.105971
Alexander J. Elias, John T. Wen
We present IK-Geo, a highly capable and computationally efficient open-source robot inverse kinematics (IK) solver. In this unifying approach, IK for any 6-DOF all-revolute (6R) manipulator is decomposed into six canonical geometric subproblems solved by intersecting circles with other geometric objects. Subproblems are efficiently solved in all cases including in a continuous and sometimes least-squares sense when a solution does not exist. This continuity requirement means IK-Geo finds all IK solutions including singular solutions and sometimes least-squares solutions. Robots with three intersecting or parallel axes are solved in closed form. All other commercially available robots have at least one pair of intersecting or parallel axes and are solved by searching over one joint angle. Fully general robots are solved by searching over two joint angles. Search solutions may be converted to a system of three or four polynomials in terms of the end effector pose in the tangent half-angle of one joint. A comparison with IKFast and the MATLAB Robotics Toolbox IK solver demonstrates that IK-Geo has faster computation and can solve more classes of robots.
{"title":"IK-Geo: Unified robot inverse kinematics using subproblem decomposition","authors":"Alexander J. Elias, John T. Wen","doi":"10.1016/j.mechmachtheory.2025.105971","DOIUrl":"10.1016/j.mechmachtheory.2025.105971","url":null,"abstract":"<div><div>We present IK-Geo, a highly capable and computationally efficient open-source robot inverse kinematics (IK) solver. In this unifying approach, IK for any 6-DOF all-revolute (6R) manipulator is decomposed into six canonical geometric subproblems solved by intersecting circles with other geometric objects. Subproblems are efficiently solved in all cases including in a continuous and sometimes least-squares sense when a solution does not exist. This continuity requirement means IK-Geo finds all IK solutions including singular solutions and sometimes least-squares solutions. Robots with three intersecting or parallel axes are solved in closed form. All other commercially available robots have at least one pair of intersecting or parallel axes and are solved by searching over one joint angle. Fully general robots are solved by searching over two joint angles. Search solutions may be converted to a system of three or four polynomials in terms of the end effector pose in the tangent half-angle of one joint. A comparison with IKFast and the MATLAB Robotics Toolbox IK solver demonstrates that IK-Geo has faster computation and can solve more classes of robots.</div></div>","PeriodicalId":49845,"journal":{"name":"Mechanism and Machine Theory","volume":"209 ","pages":"Article 105971"},"PeriodicalIF":4.5,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143591518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-08DOI: 10.1016/j.mechmachtheory.2025.105955
Sérgio B. Gonçalves , Ivo Roupa , Paulo Flores , Miguel Tavares da Silva
This work introduces the Fully Cartesian Coordinates Formulation with a Generic Rigid Body (FCC-GRB), a novel global multibody formulation for three-dimensional mechanical system analysis. The formulation's intrinsic characteristics are thoroughly detailed and compared with other widely-used global formulations, enabling its application in both kinematic and dynamic analysis of complex mechanical systems and as a teaching tool in advanced multibody dynamics courses.
FCC-GRB formulation is founded on two main premises: multibody systems are described using only Cartesian coordinates, and the rigid bodies are modeled with a fixed and predetermined structure. Consequently, the kinematic constraints are described by lower-degree equations and the system mass matrix is highly sparse. Additionally, the introduction of the generic rigid body simplifies the modeling process by making the definition of the bodies independent of system topology. To reduce the number of generalized coordinates, a reduced modeling approach using less coordinates for describing the generic rigid body is also introduced and compared with the fully-defined alternative.
The formulation's accuracy was validated through forward dynamic analysis of benchmark problems. Simulations demonstrated excellent agreement with reference data, with both modeling approaches yielding comparable kinematic results. The reduced approach offered faster computational performance, particularly in more complex models.
{"title":"Kinematic and dynamic analysis of spatial multibody systems based on a formulation with fully Cartesian coordinates and a generic rigid body","authors":"Sérgio B. Gonçalves , Ivo Roupa , Paulo Flores , Miguel Tavares da Silva","doi":"10.1016/j.mechmachtheory.2025.105955","DOIUrl":"10.1016/j.mechmachtheory.2025.105955","url":null,"abstract":"<div><div>This work introduces the Fully Cartesian Coordinates Formulation with a Generic Rigid Body (FCC-GRB), a novel global multibody formulation for three-dimensional mechanical system analysis. The formulation's intrinsic characteristics are thoroughly detailed and compared with other widely-used global formulations, enabling its application in both kinematic and dynamic analysis of complex mechanical systems and as a teaching tool in advanced multibody dynamics courses.</div><div>FCC-GRB formulation is founded on two main premises: multibody systems are described using only Cartesian coordinates, and the rigid bodies are modeled with a fixed and predetermined structure. Consequently, the kinematic constraints are described by lower-degree equations and the system mass matrix is highly sparse. Additionally, the introduction of the generic rigid body simplifies the modeling process by making the definition of the bodies independent of system topology. To reduce the number of generalized coordinates, a reduced modeling approach using less coordinates for describing the generic rigid body is also introduced and compared with the fully-defined alternative.</div><div>The formulation's accuracy was validated through forward dynamic analysis of benchmark problems. Simulations demonstrated excellent agreement with reference data, with both modeling approaches yielding comparable kinematic results. The reduced approach offered faster computational performance, particularly in more complex models.</div></div>","PeriodicalId":49845,"journal":{"name":"Mechanism and Machine Theory","volume":"209 ","pages":"Article 105955"},"PeriodicalIF":4.5,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143579016","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-05DOI: 10.1016/j.mechmachtheory.2025.105982
Yibo Jiang , Shuiguang Tong , Zheming Tong , Sheng Li , Xianmiao Yang
As crucial indicators of stability and service reliability, dynamic and tribological behaviors of gear-rotor system are investigated under both stationary and nonstationary conditions based on a new tribo-dynamic modelling approach. In the global dynamic model, the shaft compliance is considered with the gyroscopic effect, and the dynamic meshing force formulations under elastohydrodynamic and hydrodynamic lubrication states are integrated. The stepwise coupling strategy is developed to describe the two-way interaction between vibration and lubrication parameters in each time step. The methodology is validated numerically and experimentally. The investigation shows that high-speed and light-load conditions result in chaos, accompanied by extremely high subsurface stress. Higher additional torque during the acceleration and deceleration brings about rotating speed oscillation and more complex frequency components. Faster torque fluctuation contributes to multi-periodic and chaotic motions. The non-monotonic relationship with maximum pressure and minimum film thickness is also observed. Disturbing loads in the forms of sudden load variation and random load disturbance have limited impacts on system tribo-dynamic performance generally. The methodology and results provide useful guidelines for the tribo-dynamic design of gear-rotor system.
{"title":"Tribo-dynamic modelling and analysis of gear-rotor system: Effects of stationary and nonstationary conditions","authors":"Yibo Jiang , Shuiguang Tong , Zheming Tong , Sheng Li , Xianmiao Yang","doi":"10.1016/j.mechmachtheory.2025.105982","DOIUrl":"10.1016/j.mechmachtheory.2025.105982","url":null,"abstract":"<div><div>As crucial indicators of stability and service reliability, dynamic and tribological behaviors of gear-rotor system are investigated under both stationary and nonstationary conditions based on a new tribo-dynamic modelling approach. In the global dynamic model, the shaft compliance is considered with the gyroscopic effect, and the dynamic meshing force formulations under elastohydrodynamic and hydrodynamic lubrication states are integrated. The stepwise coupling strategy is developed to describe the two-way interaction between vibration and lubrication parameters in each time step. The methodology is validated numerically and experimentally. The investigation shows that high-speed and light-load conditions result in chaos, accompanied by extremely high subsurface stress. Higher additional torque during the acceleration and deceleration brings about rotating speed oscillation and more complex frequency components. Faster torque fluctuation contributes to multi-periodic and chaotic motions. The non-monotonic relationship with maximum pressure and minimum film thickness is also observed. Disturbing loads in the forms of sudden load variation and random load disturbance have limited impacts on system tribo-dynamic performance generally. The methodology and results provide useful guidelines for the tribo-dynamic design of gear-rotor system.</div></div>","PeriodicalId":49845,"journal":{"name":"Mechanism and Machine Theory","volume":"209 ","pages":"Article 105982"},"PeriodicalIF":4.5,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143550457","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-05DOI: 10.1016/j.mechmachtheory.2025.105949
J. Michael McCarthy
This paper examines Hamilton’s quaternions, dual quaternions and Clifford’s biquaternions in order to show how they are related to the kinematics of rotations in space, spatial displacements and rotations in four dimensional space. The three algebras are constructed in the same way as the even Clifford Algebras for these spaces, and their quaternion products are shown to provide a formula for spherical triangulation, spatial triangulation of lines, and double triangulation of two spherical triangles, respectively. In the process, we obtain the spherical triangle of relative rotations axes and the spatial triangle of relative screw axis, which are important generalizations of the planar pole triangle in Kinematics. We conclude with applications of double quaternions as approximations to spatial movement, which simplify calculations that rely on distance metrics for spatial positions, such as spatial motion interpolation.
{"title":"Quaternions in Kinematics","authors":"J. Michael McCarthy","doi":"10.1016/j.mechmachtheory.2025.105949","DOIUrl":"10.1016/j.mechmachtheory.2025.105949","url":null,"abstract":"<div><div>This paper examines Hamilton’s quaternions, dual quaternions and Clifford’s biquaternions in order to show how they are related to the kinematics of rotations in space, spatial displacements and rotations in four dimensional space. The three algebras are constructed in the same way as the even Clifford Algebras for these spaces, and their quaternion products are shown to provide a formula for spherical triangulation, spatial triangulation of lines, and double triangulation of two spherical triangles, respectively. In the process, we obtain the spherical triangle of relative rotations axes and the spatial triangle of relative screw axis, which are important generalizations of the planar pole triangle in Kinematics. We conclude with applications of double quaternions as approximations to spatial movement, which simplify calculations that rely on distance metrics for spatial positions, such as spatial motion interpolation.</div></div>","PeriodicalId":49845,"journal":{"name":"Mechanism and Machine Theory","volume":"209 ","pages":"Article 105949"},"PeriodicalIF":4.5,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143550458","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-03DOI: 10.1016/j.mechmachtheory.2025.105973
Jun Yang, Haoyong Yu
Incorporating system dynamics into the design of centralized control architectures is increasingly recognized as an effective approach to improve the motion control of continuum robots. However, the huge computational demands of most existing dynamic models pose significant challenges for their application in real-time control scenarios. In this paper, for hybrid-driven continuum robots, we first develop two simplified dynamic models that capture the essential dynamic characteristics while ensuring high computational efficiency. Subsequently, by incorporating the simplified models into feedback control, a robust dual-loop control framework suitable for real-time applications is presented. Specifically, the inner loop adopts these simplified models to counteract the inherent nonlinear dynamics of systems, thereby achieving a linear input/output relationship. The outer loop focuses on stabilizing the entire closed-loop system. Moreover, an extra robust term is designed and incorporated into the outer loop to mitigate the effects induced by modeling errors. Comparative experiments based on a hybrid-driven continuum robot with two segments are implemented to validate the effectiveness of these simplified models and their control synthesis.
{"title":"Robust motion control synthesis with essential dynamics for hybrid-driven continuum robots","authors":"Jun Yang, Haoyong Yu","doi":"10.1016/j.mechmachtheory.2025.105973","DOIUrl":"10.1016/j.mechmachtheory.2025.105973","url":null,"abstract":"<div><div>Incorporating system dynamics into the design of centralized control architectures is increasingly recognized as an effective approach to improve the motion control of continuum robots. However, the huge computational demands of most existing dynamic models pose significant challenges for their application in real-time control scenarios. In this paper, for hybrid-driven continuum robots, we first develop two simplified dynamic models that capture the essential dynamic characteristics while ensuring high computational efficiency. Subsequently, by incorporating the simplified models into feedback control, a robust dual-loop control framework suitable for real-time applications is presented. Specifically, the inner loop adopts these simplified models to counteract the inherent nonlinear dynamics of systems, thereby achieving a linear input/output relationship. The outer loop focuses on stabilizing the entire closed-loop system. Moreover, an extra robust term is designed and incorporated into the outer loop to mitigate the effects induced by modeling errors. Comparative experiments based on a hybrid-driven continuum robot with two segments are implemented to validate the effectiveness of these simplified models and their control synthesis.</div></div>","PeriodicalId":49845,"journal":{"name":"Mechanism and Machine Theory","volume":"209 ","pages":"Article 105973"},"PeriodicalIF":4.5,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143529805","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-28DOI: 10.1016/j.mechmachtheory.2025.105959
Daniel Condurache
This paper proposes a framework for a new computational method based on multidual nilpotent algebra calculus of the higher-order acceleration fields of the rigid body motion and multibody systems. A closed-form coordinate-free solution is presented, this result being generated by the morphism between the Lie group of the rigid body displacements and the Lie groups of the multidual homogenous matrix, orthogonal hyper-multidual tensors and, respectively, the hyper-multidual unit quaternions. The solution is implemented for higher-order kinematics analysis of lower-pair serial chains by a specific product of the exponential formula. A general method for studying the vector field of arbitrary higher-order accelerations is described. The “automatic differentiation” feature of the multi dual and hyper-multidual functions is used to obtain simultaneously a higher-order derivative of a rigid body pose. The methodologies are obtained without further differentiation of the body pose concerning time. It is proved that all information regarding the properties of the distribution of higher-order accelerations is contained in the specified multi dual homogenous matrix, or orthogonal hyper-multidual tensors, and, respectively, the unit hyper-multidual quaternions. In the case of closed kinematic chains, equations that provide higher-order kinematic constraints in the compact form are given in general form.
{"title":"An overview of higher-order kinematics of rigid body and multibody systems with nilpotent algebra","authors":"Daniel Condurache","doi":"10.1016/j.mechmachtheory.2025.105959","DOIUrl":"10.1016/j.mechmachtheory.2025.105959","url":null,"abstract":"<div><div>This paper proposes a framework for a new computational method based on multidual nilpotent algebra calculus of the higher-order acceleration fields of the rigid body motion and multibody systems. A closed-form coordinate-free solution is presented, this result being generated by the morphism between the Lie group of the rigid body displacements and the Lie groups of the multidual homogenous matrix, orthogonal hyper-multidual tensors and, respectively, the hyper-multidual unit quaternions. The solution is implemented for higher-order kinematics analysis of lower-pair serial chains by a specific product of the exponential formula. A general method for studying the vector field of arbitrary higher-order accelerations is described. The “automatic differentiation” feature of the multi dual and hyper-multidual functions is used to obtain simultaneously a higher-order derivative of a rigid body pose. The methodologies are obtained without further differentiation of the body pose concerning time. It is proved that all information regarding the properties of the distribution of higher-order accelerations is contained in the specified multi dual homogenous matrix, or orthogonal hyper-multidual tensors, and, respectively, the unit hyper-multidual quaternions. In the case of closed kinematic chains, equations that provide higher-order kinematic constraints in the compact form are given in general form.</div></div>","PeriodicalId":49845,"journal":{"name":"Mechanism and Machine Theory","volume":"209 ","pages":"Article 105959"},"PeriodicalIF":4.5,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143519902","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-28DOI: 10.1016/j.mechmachtheory.2025.105968
Zhaoyang Liu , Guang Zhao , Yunbo Yuan , Yingjie Li , Chenxin Wang , Robert G. Parker
Splines that are used in aeronautic applications often suffer contact stress concentration and sliding due to inevitable misalignment, resulting in severe fretting wear. This work proposes a composite spline consisting of a metal circular-arc external spline, an elastic spline ring, and a metal involute internal spline along with two engagement spline pairs, namely one circular-arc spline pair, and one involute spline pair. The concept of the proposed composite spline is to minimize fretting wear of the baseline metal spline and transfer the inevitable wear to the sacrificial spline ring. The inner circular-arc spline pair is interference fitted, while the outer involute spline pair is clearance fitted. A deformable and self-lubricating material, such as PEEK, is desirable for a spline ring. The design methods for the spline ring and circular-arc spline pair are developed. The high wear-resistance ability of the composite spline is validated using contact stress analysis using finite element models and wear-resistance experiments under rotating conditions with constant torques.
{"title":"Design and validation of a high wear-resistance composite spline with a sacrificial elastic ring","authors":"Zhaoyang Liu , Guang Zhao , Yunbo Yuan , Yingjie Li , Chenxin Wang , Robert G. Parker","doi":"10.1016/j.mechmachtheory.2025.105968","DOIUrl":"10.1016/j.mechmachtheory.2025.105968","url":null,"abstract":"<div><div>Splines that are used in aeronautic applications often suffer contact stress concentration and sliding due to inevitable misalignment, resulting in severe fretting wear. This work proposes a composite spline consisting of a metal circular-arc external spline, an elastic spline ring, and a metal involute internal spline along with two engagement spline pairs, namely one circular-arc spline pair, and one involute spline pair. The concept of the proposed composite spline is to minimize fretting wear of the baseline metal spline and transfer the inevitable wear to the sacrificial spline ring. The inner circular-arc spline pair is interference fitted, while the outer involute spline pair is clearance fitted. A deformable and self-lubricating material, such as PEEK, is desirable for a spline ring. The design methods for the spline ring and circular-arc spline pair are developed. The high wear-resistance ability of the composite spline is validated using contact stress analysis using finite element models and wear-resistance experiments under rotating conditions with constant torques.</div></div>","PeriodicalId":49845,"journal":{"name":"Mechanism and Machine Theory","volume":"209 ","pages":"Article 105968"},"PeriodicalIF":4.5,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143511908","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-27DOI: 10.1016/j.mechmachtheory.2025.105969
Peng Wang , Junlan Li , Qixiong Wang , Cheng Wang , Hongchang Huang , Juncheng Liu , Dawei Zhang
Deployable structures inspired by origami and kirigami are widely utilized in engineering applications. Existing origami and kirigami models have limitations in constructing large-scale deployable structures with respect to the extensibility and flatness of the working surface. To increase the deployment ratio and construct large deployable structures, this paper presents bidirectionally extensible arrays inspired by thick-panel kirigami, which have an entirely flat working surface. A two-vertex nine-crease kirigami pattern is proposed. On the basis of kinematic analysis, thick-panel kirigami models are given, and all possible crease arrangements are discussed. Several kirigami configurations are selected to construct extensible arrays. These configurations offer excellent extensibility and regular surface characteristics, which can be used to build infinite bidirectional extensible arrays. Additionally, scissor-like planar driving mechanisms are developed to achieve controllable deployment of the proposed kirigami arrays by adjusting the trajectory of feature points. A prototype of the bidirectionally extensible deployable structure is constructed, and experimental studies are conducted to validate the feasibility of the design. The proposed deployable structures show significant potential for specific engineering applications, particularly large-scale deployable structures.
{"title":"Kirigami-inspired bidirectional extensible planar deployable structures with driving mechanisms","authors":"Peng Wang , Junlan Li , Qixiong Wang , Cheng Wang , Hongchang Huang , Juncheng Liu , Dawei Zhang","doi":"10.1016/j.mechmachtheory.2025.105969","DOIUrl":"10.1016/j.mechmachtheory.2025.105969","url":null,"abstract":"<div><div>Deployable structures inspired by origami and kirigami are widely utilized in engineering applications. Existing origami and kirigami models have limitations in constructing large-scale deployable structures with respect to the extensibility and flatness of the working surface. To increase the deployment ratio and construct large deployable structures, this paper presents bidirectionally extensible arrays inspired by thick-panel kirigami, which have an entirely flat working surface. A two-vertex nine-crease kirigami pattern is proposed. On the basis of kinematic analysis, thick-panel kirigami models are given, and all possible crease arrangements are discussed. Several kirigami configurations are selected to construct extensible arrays. These configurations offer excellent extensibility and regular surface characteristics, which can be used to build infinite bidirectional extensible arrays. Additionally, scissor-like planar driving mechanisms are developed to achieve controllable deployment of the proposed kirigami arrays by adjusting the trajectory of feature points. A prototype of the bidirectionally extensible deployable structure is constructed, and experimental studies are conducted to validate the feasibility of the design. The proposed deployable structures show significant potential for specific engineering applications, particularly large-scale deployable structures.</div></div>","PeriodicalId":49845,"journal":{"name":"Mechanism and Machine Theory","volume":"209 ","pages":"Article 105969"},"PeriodicalIF":4.5,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143510129","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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