Hassan Mohamed Shams Eldin Elsayed Eleashy

06/06/2022

https://www.techscience.com/iasc/v35n1/48121

Hassan Mohamed Shams Eldin Elsayed Eleashy

Helal M, Alghtani AH, Hu JW

21/02/2022

https://www.mdpi.com/2076-3417/12/4/2238

Hassan Mohamed Shams Eldin Elsayed Eleashy

20/06/2018

https://www.sciencedirect.com/science/article/abs/pii/S0094114X17316932?via%3Dihub

Hassan Mohamed Shams Eldin Elsayed Eleashy

01/06/2018

It is important for designers of mechanical systems to visualize as many kinematic structures of mechanisms as possible. In this paper, a systematic methodology is proposed to generate all solutions of planar 8-bar kinematic chains (KCs) with up to 3 prismatic (P) pairs. First, a totally automated technique is developed to enumerate all available configurations of prismatic pairs for each KC. Second, Joint Sorting Code (JSC) is introduced for the first time to represent all KCs. Then a Kinematic Chain Structural Matrix (KCSM) is generated for all KCs to solve the problem of isomorphism. Finally, all results are evaluated by considering rules of P-joints assignment introduced by Ref. [1]. A vc++ code has been developed for enumeration, codes generation and isomorphism detection processes. The proposed methodology produces a new atlas for 8-bar chains that contains 16 groups and 48 subgroups. It contains 108, 426 and 816 KCs with 1P, 2P and 3P-joints respectively. The presented technique can be extended to single degree-of-freedom (DOF) planar n-bar chains with simple joints.

Hassan Mohamed Shams Eldin Elsayed Eleashy

01/03/2013

In this paper, a new methodology is applied to a mechanically constrain planar parallel robot formed by double 3R chains. This will transform the considered system to 8-bar mechanism. Graphical technique is introduced to enumerate all possible graphs. Then a new structural code is used to detect isomorphism and locked chains. Finally, reverse transformation is applied to construct 8-bar linkages from their corresponding graphs. As a result, a new complete atlas for 8-bar linkages is introduced for the first time, which consists of 39 linkages for independent link connections and 30 linkages for dependent link connections. Two, three and four fixed pivots are included in the proposed atlas. All enumerated linkages are compared with their corresponding kinematic chains introduced by Tsai.

Hassan Mohamed Shams Eldin Elsayed Eleashy

M.Samy Elgayyar, M.N. Shabara

01/04/2012

This paper presents a systematic methodology to convert planar 3 degree-of-freedom open 4-bar chain into planar 1 degree-of-freedom 6-bar linkages. This objective is achieved by adding 2RR chains to the original mechanism. Hence, these additional chains mechanically constrain the relative movement of the end-effector to reach a required set of task positions. Graphical enumeration technique is applied for structural synthesis of all possible 6-bar linkages. Structural code technique is introduced as a new method for structural isomorphism. The proposed methodology produces 7 different forms of 6-bar linkages.

Hassan Mohamed Shams Eldin Elsayed Eleashy

M.S.Elgayyar

01/01/2012

- In this paper, we consider the planar robot formed by 3R chain. To mechanically constrain the relative movement of the joints so that the end-effector reaches a specified set of task positions, two additional links are added to the 3R chain. Graphical representation is presented for enumeration process. Reverse transformation technique is developed to reconstruct 6-bar mechanisms from their corresponding graphs. Structural synthesis process yields designs for seven different forms of a six-bar linkage the Watt I and Stephenson I, II, and III six-bar linkages.

Hassan Mohamed Shams Eldin Elsayed Eleashy

M.Samy Elgayyar, M.N. Shabara

01/01/2012

In the present work, graphical enumeration technique is applied for structural synthesis of mechanically constrained planar parallel robot formed by single loop 6- bar chain or two 3R chains. Two RR chains are added to the considered system to mechanically constraint the movement of its end-effector. Structural code has been proposed as a new systematic methodology to detect isomorphic graphs. Therefore, 32 non-isomorphic graphs are obtained from this enumeration process. All these graphs represent one-degree-of freedom eight-bar mechanisms. Reverse transformation process is presented to obtain the corresponding linkage diagrams for all results.

Hassan Mohamed Shams Eldin Elsayed Eleashy

Mohammed ElGayyar, M. A. N. Shabara

01/01/2012

This paper presents a systematic methodology to convert planar 3 degree-of-freedom open 4-bar chain into planar 1 degree-of-freedom 6-bar linkages. This objective is achieved by adding 2RR chains to the original mechanism. Hence, these additional chains mechanically constrain the relative movement of the end-effector to reach a required set of task positions. Graphical enumeration technique is applied for structural synthesis of all possible 6-bar linkages. Structural code technique is introduced as a new method for structural isomorphism. The proposed methodology produces 7 different forms of 6-bar linkages.

Hassan Mohamed Shams Eldin Elsayed Eleashy

Mohammed ElGayyar, M. A. N. Shabara

01/01/2012

In the present work, graphical enumeration technique is applied for structural synthesis of mechanically constrained planar parallel robot formed by single loop 6bar chain or two 3R chains. Two RR chains are added to the considered system to mechanically constraint the movement of its end-effector. Structural code has been proposed as a new systematic methodology to detect isomorphic graphs. Therefore, 32 non-isomorphic graphs are obtained from this enumeration process. All these graphs represent one-degree-of freedom eight-bar mechanisms. Reverse transformation process is presented to obtain the corresponding linkage diagrams for all results.

Hassan Mohamed Shams Eldin Elsayed Eleashy

El-Gayyar, M. S.; M. Zaki

01/01/2008

In this paper, a new approach for graphical enumeration of epicyclic gear mechanisms is presented using the concept of acyclic graph. A new graphical code has been introduced to specify the priorities of all vertices of associated displacement graph. This graphical code is used to identify open graph, redundant links and isomorphic graphs. A computer program has been developed for automatic enumeration of displacement graphs as well as automatic detection of isomorphic graphs and open graphs and graphs with a redundant link without using adjacency matrices. This simplified methodology has been applied for the enumeration of epicyclic gear mechanisms with up to 12-links having up to 9 coaxial links. An atlas for 11 and 12-link mechanisms has been constructed using the proposed methodology.

Hassan Mohamed Shams Eldin Elsayed Eleashy

01/01/2006

December 2006

Hassan Mohamed Shams Eldin Elsayed Eleashy

01/01/2006

march 2006

Hassan Mohamed Shams Eldin Elsayed Eleashy

01/01/2006

February 2006

Hassan Mohamed Shams Eldin Elsayed Eleashy

M. S. El-Gayyar;Muhammad Zaki

01/01/2006

In this paper, a new approach for graphical enumeration of epicyclic gear mechanisms is presented using the concept of acyclic graph. A new graphical code has been introduced to specify the priorities of all vertices of associated displacement graph. This graphical code is used to identify open graph, redundant links and isomorphic graphs. A computer program has been developed for automatic enumeration of displacement graphs as well as automatic detection of isomorphic graphs and open graphs and graphs with a redundant link without using adjacency matrices. This simplified methodology has been applied for the enumeration of epicyclic gear mechanisms with up to 12-links having up to 9 coaxial links. An atlas for 11 and 12-link mechanisms has been constructed using the proposed methodology.