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Applying rapid heating for controlling thermal displacement of CNC lathe

Than Van-The, Wang Chi-Chang, Ngo Thi-Thao, Guo Guan-Liang

Archive of Mechanical Engineering

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2022

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LXIX, nr 3

519--539

EN

Thermal error always exists in a machine tool and accounts for a large part of the total error in the machine. Thermal displacement in X-axis on a CNC lathe controlled based on a rapid heating system is presented in this paper. Positive Temperature Coefficient (PTC) heating plates are installed on the X-axis of the machine. A control temperature system is constructed for rapid heating which further helps the thermal displacement to quickly reach stability. The system then continuously maintains stable compensation of the thermal error. The presented rapid heating technique is simpler than the compensation of machine thermal errors by interference in the numerical control system. Results show that the steady state of the thermal displacement in the X-axis can be acquired in a shorter time. In addition, thermal errors in constant and varying working conditions could be significantly reduced above 80% and 60%, respectively, compared to those without using the rapid heating. Therefore, the proposed method has a high potential for application on the CNC lathe machine for improving its precision.

2

Reduced differential transform method for thermoelastic problem in hyperbolic heat conduction domain

Chaudhari K. K., Sutar C. S.

International Journal of Applied Mechanics and Engineering

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2021

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Vol. 26, no. 1

76--87

EN

In the present study, we have applied the reduced differential transform method to solve the thermoelastic problem which reduces the computational efforts. In the study, the temperature distribution in a two-dimensional rectangular plate follows the hyperbolic law of heat conduction. We have obtained the generalized solution for thermoelastic field and temperature field by considering non-homogeneous boundary conditions in the x and y direction. Using this method one can obtain a solution in series form. The special case is considered to show the effectiveness of the present method. And also, the results are shown numerically and graphically. The study shows that this method provides an analytical approximate solution in very easy steps and requires little computational work.

3

Wpływ temperatury na naprężenia i przemieszczenia zespolonych belek mostowych

Karlikowski J.

Inżynieria i Budownictwo

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2009

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R. 65, nr 8

446-449

PL

Przedstawiono pewną procedurę obliczania naprężeń i przemieszczeń termicznych w dźwigarach zespolonych swobodnie podpartych i ciągłych, która wymaga bardzo prostych narzędzi obliczeniowych. Płyta żelbetowa ma przekrój stały, natomiast przekrój belki stalowej może być zmienny. Rozkład temperatury przyjęto stały na długości dźwigara, a w przekroju poprzecznym - liniowy na grubości płyty i stały na wysokości belki stalowej. Porównano dwa graniczne rozkłady temperatur w płycie - trójkątny i prostokątny.

EN

The procedure of computation of stresses and displacements in composite bridge beams is presented, The procedure requires simple computational tools (i. e. spreadsheet). RC slab cross-section is constant while beam cross-section may vary. Temperature distribution along girder is taken as constant and in cross-section it is assumed to be linear over slab thickness and constant over steel beam height. Two limit temperature distributions over plate thickness - triangular and rectangular - were compared.