Architecture singularity of a parallel mechanism with five degrees of freedom (DOF) is analyzed. Such mechanism consists of a movable platform connected to the base by five active limbs. Four of them are identical 6-D...Architecture singularity of a parallel mechanism with five degrees of freedom (DOF) is analyzed. Such mechanism consists of a movable platform connected to the base by five active limbs. Four of them are identical 6-DOF limbs and the last one has the same DOF as the specified DOF of the movable platform. Based on the kinematics analysis, two categories of architecture singularities for such mechanism are proposed. Then the sufficient condition for each singularity is researched. Results show that the mechanism is singular when it employs each category of the proposed architecture, provided that it satisfies the corresponding sufficient condition. It can be concluded that the proposed two categories of architecture singularities should be avoided with the following dimensional synthesis of such mechanism.展开更多
Fiumara d＇arte is an open-air museum of sculpture and contemporary art. Among the art-works of Fiumara d＇arte, the Pyramid is the last one in order of time. It is a monumental sculpture made of COR-TEN steel, by the...Fiumara d＇arte is an open-air museum of sculpture and contemporary art. Among the art-works of Fiumara d＇arte, the Pyramid is the last one in order of time. It is a monumental sculpture made of COR-TEN steel, by the artist Mauro Staccioli and it is located on one specific point of the 38th parallel of latitude, on a hill of the northern mountains of Sicily. In this study the architectural and engineering features of land art-works built in this particular plein-air park are examined and discussed. After a general description of Fiumara d＇Arte and its significance in the territory, the case of the Pyramid on the 38th parallel is focalized and a discussion of its architectural, artistic and environmental values is reported. Moreover the structural implications in its design and construction are explained, while the worst effects of external actions are underlined by showing the results of the analysis performed on a finite element model of the whole structure.展开更多
文摘Architecture singularity of a parallel mechanism with five degrees of freedom (DOF) is analyzed. Such mechanism consists of a movable platform connected to the base by five active limbs. Four of them are identical 6-DOF limbs and the last one has the same DOF as the specified DOF of the movable platform. Based on the kinematics analysis, two categories of architecture singularities for such mechanism are proposed. Then the sufficient condition for each singularity is researched. Results show that the mechanism is singular when it employs each category of the proposed architecture, provided that it satisfies the corresponding sufficient condition. It can be concluded that the proposed two categories of architecture singularities should be avoided with the following dimensional synthesis of such mechanism.
文摘Fiumara d＇arte is an open-air museum of sculpture and contemporary art. Among the art-works of Fiumara d＇arte, the Pyramid is the last one in order of time. It is a monumental sculpture made of COR-TEN steel, by the artist Mauro Staccioli and it is located on one specific point of the 38th parallel of latitude, on a hill of the northern mountains of Sicily. In this study the architectural and engineering features of land art-works built in this particular plein-air park are examined and discussed. After a general description of Fiumara d＇Arte and its significance in the territory, the case of the Pyramid on the 38th parallel is focalized and a discussion of its architectural, artistic and environmental values is reported. Moreover the structural implications in its design and construction are explained, while the worst effects of external actions are underlined by showing the results of the analysis performed on a finite element model of the whole structure.
