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The characteristics of epistemic collections are divided into two categories: accuracy (hard) and perfection (soft). The soft criterion focuses on the desired perfection; for example fluency and eloquence. This research considers the seven features of simplicity and clarity, proportionality and balance, correspondence, reciprocating, transition, symmetry and self-generation to be the most important components of soft criterion. This criterion is founded on a philosophical explanation based on transcendent wisdom. To achieve a further explanation of the components of this criterion, this indicator is included in some tables of logic, for example the table of co-true propositions. First, it is evaluated with the components of the soft criteria and while identifying some weaknesses and through philosophic analysis, in order to solve these cases, proposals are presented, implemented and improvements made to address them. The result was meaningfully positive and the suggestions increased the performance and beauty of the main tables. All the steps are descriptive-logical and the result is that with these revisions, the efficiency and usefulness of this table have increased.
 

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The stability analysis of workpiece in fixtures is considered as one of the stages of the fixture verification system. The stability of free-form workpieces in fixtures is affected by different agents including weight, locators, clamps and machining wrenches. In this study, a mathematical model has been presented for part stability analysis based on the minimum norm principle that led to a non-linear quadratic optimization problem. The solution to this problem is the reaction forces at the contact points between workpiece and locators. The study includes the workpiece stability analysis at the loading stages, determination of stability span for workpiece and the investigating the effect of the base locators distances on the workpiece stability through examples. A turbine blade model was incorporated as the case study to evaluate the suggested model capabilities in stability analysis. The loading procedure of this part into the fixture was categorized into sequential stages and its stability was investigated in contact with the locators. The results included the stability span of [15°-58°] for the workpiece on base locators, increased stability by the distanced base locators and the confirmation of the main locating plan through the stability verification at the loading stages. The results showed the model efficiency and accuracy in analyzing the free-form part stability in contact with the fixture elements. The proposed dexterous model can be integrated into the CAFD platform to be used at the early stages of locating and clamping system design applications.

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Jig and fixture design for workpieces with freeform geometry has more complexity in comparison with the polyhedral parts. The locating and clamping system design construct the basis of the jig and fixture design activities. In this study, a theoretical analysis is suggested for automatic design of clamping points for freeform workpieces. The clamping design is performed in three main stages which the clamping application points are determined through the first two principles and being verified through the last stage. The mentioned principles consist of: (1) the minimum quantity of clamps, (2) the maximum clamping force components on the locating directions and (3) the workpiece static stability under the external wrenches. After mathematical modeling, the suggested analysis was implemented into the already designed CAFD framework by the authors. Three machining models were chosen as case studies to evaluate the capabilities of the implemented system in robust design of clamping layout. The minimum quantity of clamps (single clamp for two case studies and double clamp for the third one) was designed by the developed method that verified the robustness and reliability of the suggested and implemented clamping system design model. The automatic design of clamping scheme for workpieces (regardless of the geometry) beside its capability in integration with the other modules of fixture design activities provides the opportunity for the system to be used in industrial applications.

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The magnitude of reaction forces in locating points is considered as one of the basic parameters in the fixture planning and element design stages of the fixture design procedure. The magnitude of these forces depends on the intensity, position, and orientation of the transient clamping and active machining forces and torque. Analysis of the effect of machining force and torque on reaction forces is a complex process because the magnitude, position, and orientation of machining loads change at any given time. In this paper, an analytical model is presented to investigate the effect of machining loads on online values​​ of reaction forces in the contact points between the workpiece and the fixturing elements. The magnitude ​​and direction of machining forces and torque are calculated on the tool path and using these parameters as inputs to the analytical model, the reaction forces are calculated in each of the six locators at each moment. A finite element analysis is performed to validate the values predicted by the analytical model. For this purpose, the necessary subroutines are prepared and the values ​​of the reaction forces obtained from the simulation are compared to their corresponding values ​​from the analytical model. A three-dimensional workpiece with a 3-2-1 locating system was used as a case study to evaluate the performance of the proposed model. The maximum error in calculating the reaction forces was obtained as 10.85% from the proposed analytical model which indicates the accuracy of the theoretical predictions.

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With the development of additive manufacturing technology, the quantity of devices that can be used in small office with the commercial or educational purposes increases. In this research, the goal is to build a desktop 3D printer with selective laser sintering technology, which can be used for research purposes. The main concentration is focused on fabrication with parts that can be manufactured in the country or can be procured from the domestic market. It is also tried to make the 3D printer compatible with the common open-source additive manufacturing softwares. The fabricated 3D printer has the ability to work with all kinds of common polymer powders. In addition, it is easy to update the device's firmware according to the researcher's needs. The capabilities of the device was tested with Glucose powder, paraffin wax powder, and thermoplastic-ceramic material combinations. It is currently used for research on fabricating ceramic parts with indirect laser sintering.