Abstract
Under certain load pattern, the geometrically indeterminate pin-jointed mechanisms will present certain shapes to keep static equalization. This paper proposes a matrix-based method to determine the mobility and equilibrium stability of mechanisms according to the effects of the external loads. The first and second variations of the potential energy function of mechanisms under conservative force field are analyzed. Based on the singular value decomposition (SVD) method, a new criterion for the mobility and equilibrium stability of mechanisms can be concluded by analyzing the equilibrium matrix. The mobility and stability of mechanisms can be classified by unified matrix formulae. A number of examples are given to demonstrate the proposed criterion. In the end, criteria are summarized in a table.
Similar content being viewed by others
References
Belytschko, T., Liu, W.K., Moran, B., 2000. Nonlinear Finite Elements for Continua and Structures. John Wiley & Sons, New York, US.
Fowler, P.W., Guest, S.D., 2000. A symmetry extension of Maxwell’s rule for rigidity of frames. Int. J. Solids Struct., 37(12):1793–1804. [doi:10.1016/S0020-7683(98)00326-6]
Kovács, F., 2004. Mobility and stress analysis of highly symmetric generalized bar-and-joint structures. Journal of Computational and Applied Mechanics, 5:65–78.
Kuznetsov, E.N., 1988. Underconstrained structural systems. Int. J. Solids Struct., 24(2):153–163. [doi:10.1016/0020-7683(88)90026-1]
Lengyel, A., You, Z., 2004. Bifurcations of SDOF mechanisms using catastrophe theory. Int. J. Mech. Sci., 41:559–568. [doi:10.1016/j.ijsolstr.2003.09.024]
Luo, Y.Z., 2000. Geometrical stability analysis of cable-strut tensile structures. J. Zhejiang University (Science Edition), 27:608–611 (in Chinese).
Luo, Y.Z., Dong, S.L., 2002. Nonlinear force method analysis for space truss with mobile mechanisms. Acta Mechanica Solida Sinica, 23:288–294 (in Chinese).
Maxwell, J.C., 1890. On the Calculation of the Equilibrium and Stiffness of Frames. Cambridge University Press, Cambridge, UK.
Pellegrino, S., 1990. Analysis of pre-stressed mechanisms. Int. J. Solids Struct., 26(12):1329–1350. [doi:10.1016/0020-7683(90)90082-7]
Pellegrino, S., 1993. Structure computations with the singular value decomposition of the equilibrium matrix. Int. J. Solids Struct., 30(21):3025–3035. [doi:10.1016/0020-7683(93)90210-X]
Pellegrino, S. (Ed.), 2001. Deployable Structures. CISM Course and Lectures No. 412. Springer, Wien, New York.
Pellegrino, S., Calladine, C.R., 1986. Matrix analysis of statically and kinematically indeterminate frameworks. Int. J. Solids Struct., 22(4):409–428. [doi:10.1016/0020-7683(86)90014-4]
Tarnai, T., Szabó, J., 2000. On the exact equation of inextensional, kinematically indeterminate assemblies. Comp. Struct., 75(2):145–155. [doi:10.1016/S0045-7949(99)00090-5]
Tarnai, T., Szabó, J., 2002. Rigidity and Stability of Prestressed Infinitesimal Mechanisms. In: Drew, H.R., Pellegrino, S. (Eds.), New Approaches to Structural Mechanics, Shells and Biological Structures. Kluwer, Dordrecht, p.245–256.
Author information
Authors and Affiliations
Corresponding author
Additional information
Project supported by the National Natural Science Foundation of China (Nos. 50378083 and 50638050), and the Research Foundation for the Doctoral Program of Higher Education of China (No. 20050335097)
Rights and permissions
About this article
Cite this article
Lu, Jy., Luo, Yz. & Li, N. Mobility and equilibrium stability analysis of pin-jointed mechanisms with equilibrium matrix SVD. J. Zhejiang Univ. - Sci. A 8, 1091–1100 (2007). https://doi.org/10.1631/jzus.2007.A1091
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1631/jzus.2007.A1091
Key words
- Pin-jointed mechanisms
- Criteria for stability of equilibrium
- Criteria for mobility
- Potential energy function
- Equilibrium matrix
- Singular value decomposition (SVD) method