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The purpose of this study was to investigate the thermal deformation effect of a machine tool frame on hole registration accuracy. Hole registration accuracy represents the drilling performance of a machine tool, and it greatly depends on the thermal deformation of the machine frame structures in practical engineering. Reducing thermally induced errors is crucial to improve the hole quality.

First, the thermal design of the machine frame was performed via an optimization procedure to reduce the thermal deformation at an early stage. Then, a thermal–mechanical coupling finite element method model was established to quantify the thermal deformation of the machine tool under environmental temperature fluctuations, and the validity of the presented model was confirmed experimentally using laser interferometry. Finally, a series of drilling tests, including micro-holes and medium holes, was carried out to practically investigate the hole drilling registration accuracy of the machine with a mineral casting frame under different thermal conditions.

Hole registration accuracy showed positional dependency and distinctly non-linear behaviour at different drilling axes which was closely related with the thermal conditions. The positional deviations of medium holes and micro-holes all showed an increasing trend in different degrees under the same temperature fluctuations, and the former were more sensitive to the latter. Therefore, keeping the drilling workshop under thermally stable conditions is crucial for improving the drilling performance of the machine.

The goal of this paper is to reveal the mechanism of hole registration accuracy variations with thermal fluctuations and to provide a strategy for the machine tool industry to further improve the drilling performance during the machining process.

Current lubrication analyses of misaligned journal bearings are generally performed under some given preconditions. The purpose of this paper is to calculate the lubrication characteristics of a journal bearing with journal misalignment caused by shaft deformation under load, considering the surface roughness, thermal effect and (thermal and elastic) deformation of bearing surface simultaneously.

The lubrication of bearing was analyzed by average flow model based generalized Reynolds equation. The deformation of bearing surface under pressure or heat of oil film was calculated by compliance matrix method. The compliance matrix was established by finite element analysis. The temperature distributions of oil film and bearing were calculated by energy equation and heat conduction equation.

When the thermal deformation of bearing and journal surface is considered, the radius clearance affects not only the value of the maximum oil film pressure and minimum oil film thickness, but also the distribution of oil film pressure and thickness of misaligned bearing. The effect of thermal deformation of bearing on the performance of misaligned bearing is larger than that of elastic deformation of bearing. Whether or not the surface roughness affects the performance of misaligned bearing and the affecting level depends greatly on the condition of deformation of bearing surface.

The surface roughness, thermal effect and (thermal and elastic) deformation of bearing surface were considered simultaneously in the thermoelastohydrodynamic lubrication analysis of bearing with journal misalignment caused by shaft deformation under load. The results of this paper are helpful to the design of the bearing.

The purpose of this study is to investigate the sealing performance of S-CO₂ dry gas seals (DGSs) by considering the effects of pressure-induced deformation, thermal deformation and coupling deformation.

A hydrodynamic lubrication flow model of S-CO₂ DGS was established, and the model was solved using the finite difference and finite element methods. The pressure-induced deformation and thermal deformation of the sealing ring, as well as the sealing performance under the effects of pressure-induced deformation, thermal deformation and coupling deformation, were obtained.

The deformation of the sealing ring is mainly thermal deformation. The influence of pressure-induced deformation on leakage and gas film stiffness is greater than that of thermal deformation and coupling deformation. However, thermal deformation has a greater impact on friction torque and minimum film thickness than pressure-induced deformation and coupling deformation. The influence of deformations on sealing performance is important.

The sealing performance of S-CO₂ DGSs was analyzed considering the effect of pressure-induced deformation, thermal deformation and coupling deformation, which can provide a theoretical basis for S-CO₂ DGS optimization design.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-04-2023-0120/

In high-speed processing, the influence on the machining accuracy of a machine tool is greatly caused by the thermal deformation of the motorized spindle; a further study on the thermal characteristics of the spindle is given in this paper. This study aims to reduce the thermal error and improve the performance of the machine tool by discussing the relationships between the temperature distributions and rotating accuracy caused by the thermal deformations of the spindle.

The paper opted for a method combining the theoretical analysis and the experimental study to study the thermal stability of the high-speed motorized spindle. First of all, a finite element model of the spindle was built with ANSYS, whereby temperature distributions and the thermal deformations were successively obtained at different speeds. And then, both the temperature field and the rotating accuracy of the motorized spindle were measured simultaneously by the thermal stability experiment. Finally, the experimental and theoretical results were compared and validated.

The thermal stability of the motorized spindle was studied in this paper, and some findings from the study were as follows: the spindle’s rotating accuracy maintained good in X direction but bad in Y and Z directions in terms of the deformations; the higher front-end temperature of the spindle which can significantly affect the rotating accuracy is needed to be controlled mainly; the recovery speed of the spindle deformation lagged behind the temperature’s fallback speed; the vibration graph about radial rotating sensitivity synthesized by X1 and X2 presented a trifoliate shape.

Based on a built test-bed which can synchronously measure the motorized spindle’s temperature distribution and rotating accuracy with five-point method, the coupling effects of the thermal deformation and temperature are embodied, and not only the vibration graph but also the thermal tilt angles can be gained. Therefore, considering the influence of the thermal deformation on the heat generated by the bearings, the paper fulfilled a study by which it was obtained that the front-end temperature of the spindle, which was higher and could significantly affect the rotating accuracy, needed to be controlled mainly.

This paper introduces thermal‐stress analysis methods which follow electrical engineering procedures. The spring constant or c‐value is found to be related to the electrical impedance, combining dimensions and material characteristics in a performance parameter which simplifies calculations. Voltage is used to represent thermal deformation, and thermal forces are modelled as currents. Relationships equivalent to Ohm's Law are applied to calculate thermal stresses in leads or traces of surface‐mount assemblies. The thermal performance of laminates, e.g., thermal expansion coefficients of interconnect boards with a restraining core, and the thermal stresses in the bonded layers, are derived from the analysis of an electrical network which represents the composite structure. The method provides visual concepts which facilitate a first‐order solution of engineering problems related to thermal stress.

The purpose of this paper is to propose a posture evaluation approach based on temperature compensation and three-dimensional (3-D) tolerance for the key points (KPs).

A large component 3-D compensation model of thermal deformation considering characteristics of the assembly object is developed. Then, the thermal deformation compensation model is used to modify the nominal coordinates for the KPs. By using a combination of relative deviations of KPs as the objective and 3-D tolerance as the constraints, an optimization model for posture evaluation is established.

Deviations of posture and KPs’ coordinates are obtained by solving the non-linear constrained optimization problem. The posture evaluation method is demonstrated in both a simulation case and practical implication of the aircraft components assembly system with the result that a good performance is obtained.

The proposed method has been used in several aircraft assembly projects in China, and gained a good effect.

This paper proposes a method for eliminating the affection of thermal deformation during posture evaluation process and improving the consistency and stability of posture evaluation results. The results of this research will help to systematically improve the manufacturing process and tolerance allocation efficiency in large aircraft assembly.

The purpose of this paper is to analyze the variation of temperature field, pressure field and deformation of hydrostatic thrust bearing under different working conditions, so as to provide a theoretical basis for improving accuracy and reliability.

In this study, the double rectangular hydrostatic bearing of type Q1-224 was selected as the research object, and the simulation was carried out according to different working conditions, and the obtained data were summarized regularly.

It is found that the overall temperature of hydrostatic bearing increases with the increase of speed and load, and the increase in load will result in a larger pressure distribution which first increases and then decreases with the speed. The deformation trend of the deformation field is found, and it is found that the force deformation is larger than the thermal deformation at low rotational speed, and the thermal deformation is larger than the force deformation at high rotational speed.

In this study, the fluid-structure coupling method of conjugate heat transfer is applied to study the whole hydrostatic bearing. Most of the previous studies only studied the oil film and considered the influence of the convective heat transfer between the hydrostatic bearing and the air in heat transfer, which is rarely seen in the previous research literature.

The purpose of this study is to propose a fractal model of thermal contact conductance (TCC) of rough surfaces considering substrate deformation. Three deformation modes of the asperity of the rough surface are considered, including elastic deformation, elastic–plastic deformation and full plastic deformation.

The influences of contact load, fractal dimension and fractal roughness on the TCC of the rough surface were studied.

The results show that the TCC of the rough surface increases with the increase of contact load. When D > 2.5, the larger the fractal dimension, the higher the increased rate of the TCC of the rough surface with the increase of contact load. The TCC of the rough surface increases with the increase of fractal dimension and decreases with the increase of fractal roughness. The TCC of the rough surface can be achieved by selecting a contact surface with roughness.

A fractal model of TCC of rough surfaces considering substrate deformation was established in this study. The achievements of this study provide some theoretical basis for the investigation of TCC of rough surfaces.

The purpose of this paper is to propose a set of constitutive functions for dried bodies for accurate prediction of the entire deformation process of ceramic products during firing and to present relevant methods for determining their coefficients from a series of respective thermo-mechanical analysis (TMA) tests.

The function forms of the sintering-induced strain rate, viscoplastic multiplier and elastic modulus are formulated in order with reference to empirical data of relative densities. Separate TMA tests are conducted to identify their coefficients, while a stairway thermal cycle test is carried out to identify the parameters in the densification rate. Then, various finite element analyses (FEA) are performed for accuracy confirmation.

The performances of the present constitutive functions along with the identified material parameters were validated in comparison with the relevant test results. It has then been confirmed that these functions enable us to some extent to accurately estimate the non-mechanical and mechanical deformations of dried bodies during firing. Also, by performing FEA of an actual sanitary ware product, the applicability and capability of the proposed set of constitutive functions could be demonstrated.

The present methodology with the proposed constitutive functions is a simple, but reliable and practical approach for simulating the deformation process of arbitrary ceramic products subjected to firing and applicable for practical applications in various engineering fields.

The constitutive functions of the viscoplastic multiplier and elastic modulus, which enable us to properly characterize the mechanical behavior of dried bodies subjected to firing, are originally formulated in analogy with that of the sintering-induced strain.

The purpose of this paper is to analyze the effect of the space thermal effect on satellite antenna.

In this paper, according to the geometric characteristics of parabolic reflector, the transient temperature field of an element along its thickness direction is built for shell structures using finite element discretization and the quadratic function interpolation, and heat conduction equations are derived based on the theory of the thermo-elastic dynamics. The modeling theory of rigid–flexible coupling system considering thermal effect is extended to the satellite antenna system. Then, the coupling dynamic equations are established including coupling stiffness matrix and thermal loaded undergoing a large overall motion. Finally, an adaptive controller is proposed and the adaptive update laws are designed under the parameter uncertainty.

The results of dynamic characteristic analysis show that the dynamic thermal loaded coupled with structure deformation induce the unstable vibration and coupled flutter. Further, the coupling effect degrades the antenna pointing accuracy seriously and leads to disturbances on satellite base. The results of the simulation show that the adaptive controller can ensure that antenna pointing closes to the expected trajectory progressively, and it demonstrates that the proposed control scheme is feasible and effective.

The paper considers only the effect of space thermal effect to satellite antenna. Further research could be done on the flexible multibody system by considering joint clearance in the future research.

The conclusions of this paper would be an academic significance and engineering value for the analysis and control of satellite antenna pointing.