scholarly journals Evaluation of coordinate measurement uncertainty of parallelism of axes by means of sensitivity analysis method

Mechanik ◽  
2018 ◽  
Vol 91 (12) ◽  
pp. 1136-1139
Author(s):  
Wojciech Płowucha

The examples of measurement of three variants of the parallelism of the connecting-rod center axes the theoretical basis of a new method for estimating the uncertainty of coordinate measurements. This is a continuation of the article “Estimation of coordinate measurement uncertainty – theoretical fundamentals” (Mechanik 11, 2018). In the first variant, this tolerance field is in the form of a cylinder, in the other two it has the form of a pair of planes. In the examples presented, uncertainty budgets contain six or nine input factors. In all cases, when the axes of the measured holes are parallel to one of the machine axes, only two input factors affect the uncertainty of the measurement of parallelism deviation.

2021 ◽  
Vol 18 ◽  
pp. 100274
Author(s):  
Mirosław Wojtyła ◽  
Paweł Rosner ◽  
Alistair B. Forbes ◽  
Enrico Savio ◽  
Alessandro Balsamo

Author(s):  
Guang Dong ◽  
Zheng-Dong Ma ◽  
Gregory Hulbert ◽  
Noboru Kikuchi ◽  
Sudhakar Arepally ◽  
...  

Efficient and reliable sensitivity analyses are critical for topology optimization, especially for multibody dynamics systems, because of the large number of design variables and the complexities and expense in solving the state equations. This research addresses a general and efficient sensitivity analysis method for topology optimization with design objectives associated with time dependent dynamics responses of multibody dynamics systems that include nonlinear geometric effects associated with large translational and rotational motions. An iterative sensitivity analysis relation is proposed, based on typical finite difference methods for the differential algebraic equations (DAEs). These iterative equations can be simplified for specific cases to obtain more efficient sensitivity analysis methods. Since finite difference methods are general and widely used, the iterative sensitivity analysis is also applicable to various numerical solution approaches. The proposed sensitivity analysis method is demonstrated using a truss structure topology optimization problem with consideration of the dynamic response including large translational and rotational motions. The topology optimization problem of the general truss structure is formulated using the SIMP (Simply Isotropic Material with Penalization) assumption for the design variables associated with each truss member. It is shown that the proposed iterative steps sensitivity analysis method is both reliable and efficient.


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