Mechanism and Machine Theory

This is the Mathematica and Matlab code implementation of the modeling formulation introduced in the article "Dynamics of Parallel Manipulators with Hybrid Complex Limbs -- Modular Modeling and Parallel Computing" https://doi.org/10.1016/j.mechmachtheory.2021.104549

All synthesized Assur groups with 2-12 links are collected and listed in the PDF file.

The folder contains files for a multi-software automatic framework, capable of analyzing the performances of a Contact-Aided Cross-Axis pivot. Chained-Beam-Constraint Model and batch 1D FEA are launched from Matlab environment.

Mathematica implementation of the presented formulae

different parameters of each limit cycle

Maple code to generate the polynomial coefficients required to compute generalized Burmester code This code has been used for the analytical computations presented in Cera, M., Pennestri, E., Generalized Burmester points computation by means of Bottema’s instantaneous invariants and intrinsic geometry, Mechanism and Machine Theory, 2018, 129(November), pp. 316-335

The research data is divided into two parts. Some of them are experimental observation data of jumping process of locust, which reflects the jumping stability of locust. Other part of the data reflects the jumping stability of locust-inspired jumping robot, which includes kinematic and dynamic stability. The data results show that the robot has good jumping stability based on the mechanism design method proposed in this paper.

Relationship between the external torque and tension force acting on the pulley is equivalent to the transmission ratio, which is the radius of the pulley. If the radius of the pulley is changed by an external torque, the transmission ratio can be changed passively. A new variable-radius pulley has been developed and reported, in which the radius is changed passively according to the external torque. The goal of this work was to demonstrate the concept of a variable transmission system (variable-radius pulley) by measuring and comparing the tension forces and external torques. This work showed that the transmission ratio is increased as the external torque increases by changing the radius of pulley

This data provides the dynamic response, from both time domain and frequency domain, of the PRB models and FEA models for CPGMs. The data shows the effects of the design and input parameters on the accuracy of dynamic performance of the PRB models. Specifically, the studied parameters include λ,A,and ω, where λ is defined as the mass ratio of the tip mass (mt) over the beam mass (mb), and A and ω are the magnitude and frequency of the input force of F=A sin⁡〖(2πωt)〗. The problem statement and modeling procedure of the PRB models are presented in She et al. [1], and the original raw data is provided as the supplemental material.

The Excel file contains comparison of DAS3D results with Abaqus FE simulations. Accuracy of single sheet and wire flexures of different dimensions are investigated under various loading cases. The effect of dividing sheet and wire flexures into multiple segments is also investigated. Performance of single element hinge (circular, elliptic and filleted type) is compared with Abaqus FEA. Accuracy of three complex flexure mechanisms, double parallelogram, 3D sheet stage and 3D wire stage, compared to Abaqus FE simulations are studied in individual worksheets.