Moatimid Galal M, Amer T S, Galal Abdallah A
Department of Mathematics, Faculty of Education, Ain Shams University, Cairo, Egypt.
Department of Mathematics, Faculty of Science, Tanta University, Tanta, 31527, Egypt.
Sci Rep. 2025 May 7;15(1):15883. doi: 10.1038/s41598-025-99645-x.
Pendulum oscillators study harmonic motion, energy conservation, and nonlinear dynamics, providing insights into mechanical vibrations, wave phenomena, weather patterns, and quantum mechanics, with real-world applications in engineering, seismology, and clock mechanisms. The present study addresses three distinct issues related to SPs; a charged magnetic spherical simple pendulum (SP), and a SP composed of heavy cylinders that roll freely in a horizontal plane, and a nonlinear model depicting the motion of a damped SP in a fluid flow. The SPs are analyzed via an innovative technology known as the non-perturbative approach (NPA), which is based on He's frequency formula (HFF). This advanced approach linearizes a nonlinear ordinary differential equation (ODE), enabling more straightforward analysis and solution. As-well known, implementing the NPA has several advantages, chief among them the removal of the constraints associated with managing Taylor expansions. Consequently, there have been no augmentations to the current restorative forces. Secondly, the novel method enables us to assess the stability criteria of the system away from the traditional perturbation techniques. The numerical comparison of nonlinear ODEs into linear ones using Mathematica Software (MS) is conducted to validate this innovative method. An analysis of the two responses demonstrates a strong concordance, underscoring the necessity of precision of the methodology. Furthermore, to demonstrate the influence of the components on motion behavior, the time history of the calculated solution and the corresponding phase plane plots are accumulated. The use of multiple phase portraits aims to explore stability and instability near equilibrium points by examining the interaction between expanded and cyclotron frequencies, modulated by the magnetic field, for varying azimuthal angular velocities.
摆式振荡器研究简谐运动、能量守恒和非线性动力学,为机械振动、波动现象、天气模式和量子力学提供见解,并在工程、地震学和时钟机构中有实际应用。本研究解决了与球形摆(SP)相关的三个不同问题;一个带电磁球形单摆(SP),一个由在水平面上自由滚动的重圆柱体组成的SP,以及一个描述阻尼SP在流体流中运动的非线性模型。通过一种称为非微扰方法(NPA)的创新技术对SP进行分析,该技术基于何氏频率公式(HFF)。这种先进方法将非线性常微分方程(ODE)线性化,使分析和求解更直接。众所周知,实施NPA有几个优点,其中主要的优点是消除了与处理泰勒展开相关的约束。因此,目前的恢复力没有增加。其次,这种新方法使我们能够远离传统微扰技术来评估系统的稳定性标准。使用Mathematica软件(MS)对非线性ODE转化为线性ODE进行数值比较,以验证这种创新方法。对两种响应的分析表明有很强的一致性,强调了该方法精确性的必要性。此外,为了证明各组件对运动行为的影响,积累了计算解的时间历程和相应的相平面图。使用多个相图旨在通过研究由磁场调制的扩展频率和回旋频率之间的相互作用,来探索平衡点附近的稳定性和不稳定性,其中扩展频率和回旋频率随方位角速度而变化。