Acta Mechanica Sinica最新文献

{"title":"Topology optimization of open radiation shielding structures","authors":"Junhao Wu \u0000 (,&nbsp;),&nbsp;Baoshou Liu \u0000 (,&nbsp;),&nbsp;Mingyang Zhang \u0000 (,&nbsp;),&nbsp;Zhongao Ji \u0000 (,&nbsp;),&nbsp;Lai Wei \u0000 (,&nbsp;),&nbsp;Xue Ling \u0000 (,&nbsp;),&nbsp;Yinan Cui \u0000 (,&nbsp;)","doi":"10.1007/s10409-026-25911-x","DOIUrl":"10.1007/s10409-026-25911-x","url":null,"abstract":"<div><p>How to design lightweight radiation shielding structures is a key scientific challenge in fields such as nuclear energy and deep space exploration. Due to functional requirements, these shielding structures are often partially open, making classical design approaches difficult to apply directly to complex configurations. Machine learning-based design methods, while capable of handling complex geometries, often suffer from excessive design freedom, leading to high training costs. Therefore, developing efficient methods for lightweight shielding structure design is of critical importance. In this work, a topology optimization method is proposed for the first time to achieve the lightweight design of a gamma-ray shielding structure. The method employs an analytical model of radiation attenuation based on the law of energy flux conservation and the exponential decay law. We demonstrate the effectiveness and universality of the method through the optimization design for various opening shapes and multiple volume constraints for 2D and 3D cases, using the best shielding performance as the optimization goal. Results indicate that, typically, folding the opening channel once is sufficient to achieve optimal shielding effectiveness. The optimized structure is scalable, allowing for the direct transfer of optimized structures to engineering components.</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":7109,"journal":{"name":"Acta Mechanica Sinica","volume":"42 11","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148465994","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"In vitro wrist blood pressure simulation system for experimental analysis of factors affecting oscillometric pressure measurement","authors":"Yongtao Liu \u0000 (,&nbsp;),&nbsp;Ying He \u0000 (,&nbsp;),&nbsp;Taiqi Lu \u0000 (,&nbsp;),&nbsp;Jian Yao \u0000 (,&nbsp;),&nbsp;Dengji Liu \u0000 (,&nbsp;),&nbsp;Huimin Chen \u0000 (,&nbsp;),&nbsp;Qingzhuo Chi \u0000 (,&nbsp;)","doi":"10.1007/s10409-025-25898-x","DOIUrl":"10.1007/s10409-025-25898-x","url":null,"abstract":"<div><p>Accurate determination of systolic and diastolic blood pressure from the oscillometric cuff-pressure oscillation envelope remains a key challenge in daily monitoring. This study aims to design wrist silicone phantoms based on personalized magnetic resonance imaging and to employ an <i>in vitro</i> pulsatile experimental platform to investigate how wrist physiological parameters affect the envelope. Silicone materials with elastic moduli matched to those of wrist soft tissues and arteries were selected, and biomimetic wrist phantoms were fabricated by integrating 3D printing and silicone casting techniques. The image-based silicone wrist phantom was incorporated into an <i>in vitro</i> pulsatile platform to establish an <i>in vitro</i> wrist blood pressure simulation system (IV-WBPSS). Several representative human blood pressure conditions were set in the IV-WBPSS, and the oscillometric envelopes of the simulated wrists were acquired using a modified Omron T31 sphygmomanometer. By comparing the envelope characteristic parameters of silicone and human wrists under identical blood pressure conditions, the physiological relevance of the IV-WBPSS was validated. Further experiments were performed to obtain oscillometric envelopes and their characteristic parameters under various pulse pressure (PP) and arterial stiffness conditions. Results show that the characteristic parameters of the wrist oscillometric envelope are highly correlated with the internal radii and stiffness of the radial and ulnar arteries. The findings also indicate that the general amplitude coefficient exhibits substantial errors in systolic blood pressure (SBP) extraction under conditions of low PP and high PP. To address this limitation, this study proposes a pulse-pressure-stratified calibration method, which involves setting SBP amplitude coefficients by PP groups and can effectively improve the accuracy of wrist oscillometric blood pressure measurement. This study provides new insights into improving the accuracy of wrist oscillometric blood pressure measurement, and the IV-WBPSS offers a useful tool for performance evaluation of wearable medical devices.</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":7109,"journal":{"name":"Acta Mechanica Sinica","volume":"42 10","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148465534","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A distribution function correction-based immersed boundary Lattice Boltzmann method for gas-liquid-solid multiphase flows","authors":"Mufeng Chen \u0000 (,&nbsp;),&nbsp;Xiaodong Niu \u0000 (,&nbsp;),&nbsp;Peng Yu \u0000 (,&nbsp;),&nbsp;Jingfeng Ye \u0000 (,&nbsp;),&nbsp;Kangyang Zeng \u0000 (,&nbsp;),&nbsp;Jiaqing Li \u0000 (,&nbsp;),&nbsp;Xiang Li \u0000 (,&nbsp;)","doi":"10.1007/s10409-026-25818-x","DOIUrl":"10.1007/s10409-026-25818-x","url":null,"abstract":"<div><p>This study proposes an enhanced immersed boundary-lattice Boltzmann method (IB-LBM) incorporating distribution function correction for gas-liquid-solid multiphase flow simulations. The methodology characterizes the fluid-solid interactions disturbing the surrounding fluid through non-equilibrium distribution function analysis within the IB-LBM framework. A phase-field approach coupled with the conservative Allen-Cahn equation governs gas-liquid interface evolution, while an integrated scheme combining weighted capillary force calculation and diffused interface immersion boundary treatment addresses dynamic wetting phenomena at moving contact lines. Validation through four typical benchmark simulations, i.e., (1) a droplet spreading on a cylinder, (2) particle wetting behavior at a gas-liquid interface, (3) a circular cylinder submersion through an air-water interface, and (4) interfacial self-assembly of a triple-particle system, demonstrates the method’s reliability. Then, a systematic study of a particle that falls and collides with another particle at the air-water interface is conducted to investigate further the phase-significant deformation phenomenon accompanied by complex particle interaction in multiphase flow. Numerical simulations confirm the method’s capability to accurately model multiphase systems with multiple particles while maintaining mass conservation principles.</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":7109,"journal":{"name":"Acta Mechanica Sinica","volume":"42 11","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148465620","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical investigation of the compressible flow structure of ventilated supercavities with two closure types","authors":"Haiyu Xu \u0000 (,&nbsp;),&nbsp;Zerui Wu \u0000 (,&nbsp;),&nbsp;Daijin Li \u0000 (,&nbsp;),&nbsp;Chuang Huang \u0000 (,&nbsp;),&nbsp;Kai Luo \u0000 (,&nbsp;),&nbsp;Kai Qin \u0000 (,&nbsp;),&nbsp;Jianjun Dang \u0000 (,&nbsp;),&nbsp;Yongjun Pan \u0000 (,&nbsp;)","doi":"10.1007/s10409-026-25637-x","DOIUrl":"10.1007/s10409-026-25637-x","url":null,"abstract":"<div><p>This study investigates the internal flow regime of ventilated supercavities featuring two closure types: twin-vortex and re-entrant jet. A solver based on the inhomogeneous multiphase model was developed to predict the supercavitation flow. The effectiveness of the numerical model was thoroughly validated against experimental data. Furthermore, a comprehensive analysis was conducted to elucidate the internal flow structure and examine the transient flow behavior associated with both twin-vortex and re-entrant jet supercavities. The results indicate that a flow structure characterized by gas recirculation, which includes both the reverse flow region and downstream flow region, is present within both types of supercavities. In twin-vortex supercavities, the interaction between the two opposing flow domains leads to significant transient characteristics and substantial deformation of the interface. An increase in the ventilation rate diminishes the fluctuation characteristics of the supercavity geometry; however, the internal gas flow remains intense and complex. In the case of re-entrant jet supercavities, the vertical extent of the downstream flow region is smaller compared to that of the reverse flow region. Additionally, the ratio of the vertical extent of the downstream flow region to the cross-sectional dimension of the supercavity is contingent upon the geometry of the supercavitating vehicle.\u0000</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":7109,"journal":{"name":"Acta Mechanica Sinica","volume":"42 10","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148465281","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Repulsive magnetism-based permanent magnetic thrust bearings: a comprehensive study of theories and experiments","authors":"Rui Li \u0000 (,&nbsp;),&nbsp;Chang Qi \u0000 (,&nbsp;),&nbsp;Dongming Guo \u0000 (,&nbsp;),&nbsp;Wei Liu \u0000 (,&nbsp;),&nbsp;Hao Chen \u0000 (,&nbsp;),&nbsp;Liqiang Han \u0000 (,&nbsp;),&nbsp;Mengtong Wang \u0000 (,&nbsp;),&nbsp;Lianzheng Pei \u0000 (,&nbsp;),&nbsp;Shu Yang \u0000 (,&nbsp;)","doi":"10.1007/s10409-026-25799-x","DOIUrl":"10.1007/s10409-026-25799-x","url":null,"abstract":"<div><p>A repulsive magnetism-based permanent magnetic thrust bearing (RMPMTB), tailored for higher vibration demand marine applications, is proposed to enhance vibration isolation and proven to be feasible. It compensates for the widely-used attractive magnetism-based PMTB (AMPMTB), which has approached its theoretical performance ceiling. This study presents a comprehensive analysis, combining theoretical modeling of the magneto-vibration isolation mechanism and experimental validation on both multi-physical theory and potential applications. A nonlinear magnetic field model of the RMPMTB is developed, and a quantitative comparative analysis of its mechanical properties against the AMPMTB is conducted, elucidating the fundamental mechanism behind its superior vibration isolation capability. Additionally, the longitudinal nonlinear dynamic model of the RMPMTB demonstrates unique hardening and softening behaviors under varying static and dynamic loads. Experimental validation, including quasi-static, harmonic, and white noise excitations, confirms the accuracy of the magnetic and dynamic models. The experimental results show that the RMPMTB prototype outperforms the AMPMTB prototype in vibration isolation under light-load conditions, presenting a promising solution for various advanced applications.\u0000</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":7109,"journal":{"name":"Acta Mechanica Sinica","volume":"42 10","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148465647","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Al-Ti interpenetrating phase composites with high strength and specific energy absorption fabricated by additive manufacturing and hot-pressing sintering","authors":"Mingyang Zhang \u0000 (,&nbsp;),&nbsp;Zhangtao Li \u0000 (,&nbsp;),&nbsp;Junhao Wu \u0000 (,&nbsp;),&nbsp;Junye Li \u0000 (,&nbsp;),&nbsp;Zhun Liang \u0000 (,&nbsp;),&nbsp;Changmeng Liu \u0000 (,&nbsp;),&nbsp;Gaoyang Mi \u0000 (,&nbsp;),&nbsp;Chunming Wang \u0000 (,&nbsp;),&nbsp;Yinan Cui \u0000 (,&nbsp;)","doi":"10.1007/s10409-026-51027-x","DOIUrl":"10.1007/s10409-026-51027-x","url":null,"abstract":"<div><p>In this study, lightweight and high-strength aluminum-titanium (Al-Ti) interpenetrating phase composites (IPCs) were successfully synthesized by integrating additive manufacturing with hot-pressing sintering, which overcomes the well-known issue of immiscible interface. The Ti6Al4V lattice structure acted as reinforcement of AlMgScZr alloy. A diffusion dominated interface was formed between Ti6Al4V and AlMgScZr, and no brittle phase such as Al₃Ti was found. Al-Ti IPCs demonstrate an excellent combination of strength and specific energy absorption. Systematic experiments and simulations reveal two key mechanisms underlying this synergy: (1) the Ti6Al4V skeleton suppresses damage propagation, enhancing structural integrity compared to monolithic AlMgScZr alloys; (2) the AlMgScZr alloy matrix stabilizes the Ti6Al4V lattice against buckling. This work provides new insights into designing lightweight IPCs with superior mechanical performance.\u0000</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":7109,"journal":{"name":"Acta Mechanica Sinica","volume":"42 10","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148465650","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Curvature shaping control of nonlinear mechanical systems","authors":"Benliang Wang \u0000 (,&nbsp;),&nbsp;Yongxin Guo \u0000 (,&nbsp;),&nbsp;Donghua Shi \u0000 (,&nbsp;)","doi":"10.1007/s10409-026-25168-x","DOIUrl":"10.1007/s10409-026-25168-x","url":null,"abstract":"<div><p>This paper introduces a curvature-shaping approach for stabilizing nonlinear mechanical systems. The procedure involves modifying the metric to change curvature, thus making the geodesics corresponding to the closed-loop system confined within a prescribed region. The control laws realizing curvature shaping are derived for fully actuated and underactuated systems, respectively. First, a criterion for Jacobi stability is given in terms of the sectional curvature. The feedback control law is then obtained for fully actuated systems on locally conformally flat Riemannian manifolds. The control law manifests as a physically realizable potential field and generates a “curvature well” with a boundary possessing a curvature singularity. Next, a control law for an underactuated system is constructed to make the controlled horizontal metric negative definite and the curvature at the equilibrium point positive. Specific matching conditions are needed to realize the control. Finally, the effectiveness of the proposed approach is demonstrated through the stabilization of the cart-pendulum system. The curvature shaping method reduces stability verification to a scalar sectional curvature, facilitates intuitive parameter tuning, and suggests a promising geometric framework for robust control design in robotics and aerospace systems.</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":7109,"journal":{"name":"Acta Mechanica Sinica","volume":"42 10","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148465499","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multi-objective optimization of cooling pipeline stability for the Hefei Advanced Light Facility","authors":"Guanghui Han \u0000 (,&nbsp;),&nbsp;Xinyu Lian \u0000 (,&nbsp;),&nbsp;Jixia Yi \u0000 (,&nbsp;),&nbsp;Huaxia Deng \u0000 (,&nbsp;),&nbsp;Mengchao Ma \u0000 (,&nbsp;),&nbsp;Xiang Zhong \u0000 (,&nbsp;),&nbsp;Yang Peng \u0000 (,&nbsp;),&nbsp;Zhanglang Xu \u0000 (,&nbsp;),&nbsp;Shen Wei \u0000 (,&nbsp;),&nbsp;Xinglong Gong \u0000 (,&nbsp;)","doi":"10.1007/s10409-025-25675-x","DOIUrl":"10.1007/s10409-025-25675-x","url":null,"abstract":"<div><p>Flow-induced vibration in the cooling pipeline is a significant source of instability that threatens the precision of the variable-angle plane grating monochromator (VA-PGM) at the Hefei Advanced Light Facility. To address this challenge, a comprehensive framework integrating sensitivity analysis and multi-objective optimization is employed to optimize the pipeline structural design and reduce flow-induced vibration. A parametric finite element analysis of the pipeline is developed to investigate the sensitivity of geometric parameters, and a response sample space is generated through fluid-structure interaction simulations. A meta-model of optimal prognosis (MOP) is then constructed to approximate the system’s behavior for global sensitivity analysis, which integrates surrogate model selection and evaluation to automatically determine the most appropriate meta-model. The established MOP ensures that the sensitivity analysis is based on the optimal meta-model, identifying the bending radius and angle as the key factors influencing vibration characteristics. An evolutionary algorithm methodology is adopted for multi-objective optimization based on the constructed MOP, resulting in the optimal combination of geometric parameters that minimizes vibration displacement. The optimized geometric parameters are validated through comprehensive VA-PGM simulations, resulting in a 52.5% reduction in the maximum relative angular vibration displacement between critical optical components. This demonstrates the effectiveness of the comprehensive framework, providing a reference solution for the structural stability design of advanced light facilities.</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":7109,"journal":{"name":"Acta Mechanica Sinica","volume":"42 10","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148465310","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Three-dimensional simulation of non-Newtonian effects on droplet coalescence in an electric field","authors":"Weilin Chen \u0000 (,&nbsp;),&nbsp;Lei Wang \u0000 (,&nbsp;),&nbsp;Dinggen Li \u0000 (,&nbsp;),&nbsp;Bo Xu \u0000 (,&nbsp;)","doi":"10.1007/s10409-026-25777-x","DOIUrl":"10.1007/s10409-026-25777-x","url":null,"abstract":"<div><p>In this work, the three-dimensional phase-field-based lattice Boltzmann method is adopted to investigate the non-Newtonian effects on droplet coalescence in an electric field. The numerical approach is validated by simulating droplet deformation in a uniform electric field and two-phase non-Newtonian flow between two plates. Results show that size asymmetry induces asymmetric deformation: smaller droplets tend to flatten while larger ones elongate along the electric field. Non-Newtonian rheology further modulates this deformation—shear-thinning fluids promote oblate shapes, while shear-thickening fluids enhance axial elongation. Moreover, both droplet size asymmetry and non-Newtonian rheology significantly influence the approach time prior to coalescence. In addition, increasing the electric capillary number further amplifies droplet deformation and accelerates coalescence. Due to their distinct rheological responses, shear-thinning fluids undergo a more rapid reduction in apparent viscosity during approach, promoting faster coalescence, whereas shear-thickening fluids experience greater viscous resistance, limiting acceleration. These results underscore the coupled effects of droplet size asymmetry, electric forcing, and fluid rheology in governing droplet dynamics under electric fields.</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":7109,"journal":{"name":"Acta Mechanica Sinica","volume":"42 11","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148465311","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Power-bounded inverted pendulum model for maximum speed analysis in bipedal robots: a dual constraint mechanism","authors":"Chengkai Su \u0000 (,&nbsp;),&nbsp;Chaojie Fu \u0000 (,&nbsp;),&nbsp;Yanhong Liang \u0000 (,&nbsp;),&nbsp;Kaixin Lan \u0000 (,&nbsp;),&nbsp;Yongbin Jin \u0000 (,&nbsp;),&nbsp;Hongtao Wang \u0000 (,&nbsp;),&nbsp;Wei Yang \u0000 (,&nbsp;)","doi":"10.1007/s10409-026-25928-x","DOIUrl":"10.1007/s10409-026-25928-x","url":null,"abstract":"<div><p>Replicating biological systems’ agile locomotion remains challenging in legged robotics, evidenced by substantial performance gaps between humans and the state-of-the-art bipedal robots in running. Analysis of intrinsic speed limits in bipedal running remains less developed, despite progress in controller design. Inspired by human biomechanics, the present work proposed the power-bounded inverted pendulum (PBIP) model that incorporates the leg power saturation effect. The PBIP model characterizes the maximum running speed of bipedal robots over a complete set of gait parameters, revealing two distinct speed-limiting mechanisms: geometry constraints dominate at low-frequency gaits, and power saturation dictates speed limitation at high-frequency gaits. Simulation of LimX Dynamics Tron, Unitree-G1, and Unitree-H1 robots verified the universality of the dual speed constraint mechanism in physical robot systems. Applying the PBIP model to optimize joint motor parameters, we reduced leg power consumption by 18.0% while increasing the maximum speed of the Tron robot by 0.26 m s⁻¹. Furthermore, the maximum speeds of the G1 and H1 robots were raised by 0.09 and 0.51 m s⁻¹, respectively. The PBIP model provides a rapid evaluation tool for balancing leg geometry and the actuator power, serving the design of highly agile bipedal robots in engineering practice.</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":7109,"journal":{"name":"Acta Mechanica Sinica","volume":"42 10","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148465498","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}