Application of Modal Analysis to Building Simulation Models of Thermal Processes in Machine Tools

Author(s):  
A. N. Polyakov ◽  
I. P. Nikitina
Buildings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 242
Author(s):  
Christoph Schünemann ◽  
David Schiela ◽  
Regine Ortlepp

Can building performance simulation reproduce measured summertime indoor conditions of a multi-residential building in good conformity? This question is answered by calibrating simulated to monitored room temperatures of several rooms of a multi-residential building for an entire summer in two process steps. First, we did a calibration for several days without the residents being present to validate the building physics of the 3D simulation model. Second, the simulations were calibrated for the entire summer period, including the residents’ impact on evolving room temperature and overheating. As a result, a high degree of conformity between simulation and measurement could be achieved for all monitored rooms. The credibility of our results was secured by a detailed sensitivity analysis under varying meteorological conditions, shading situations, and window ventilation or room use in the simulation model. For top floor dwellings, a high overheating intensity was evoked by a combination of insufficient use of night-time window ventilation and non-heat-adapted residential behavior in combination with high solar gains and low heat storage capacities. Finally, the overall findings were merged into a process guideline to describe how a step-by-step calibration of residential building simulation models can be done. This guideline is intended to be a starting point for future discussions about the validity of the simplified boundary conditions which are often used in present-day standard overheating assessment.


Procedia CIRP ◽  
2018 ◽  
Vol 77 ◽  
pp. 473-476 ◽  
Author(s):  
Jan Berthold ◽  
Martin Kolouch ◽  
Volker Wittstock ◽  
Matthias Putz

2019 ◽  
Vol 295 ◽  
pp. 67-72
Author(s):  
Zhong Peng Zheng ◽  
Xin Yang Jiang ◽  
Xin Jin

In order to improve the dynamic stability of precision micro slitting turn-milling machine tools, reduce or avoid the vibration problem during the cutting process, optimize the machine structure and processing parameters, the modal analysis of precision micro slitting turn-milling machine tool based on hammer experimental method was researched. In this paper, by analyzing the mechanism of precision micro slitting turn-milling machine tools, the multi degree-of-freedom mathematical vibration model of precision slitting turn-milling machine tools is constructed. The precision micro turn-milling machine tool is analyzed based on the hammer experiment analysis. The modal analysis obtained the first five natural frequencies and resonance speeds of the precision micro slitting turn-milling machine tool,including ST26, NN-25UB8K2 and NN-20UB87. The research results show that hammer experimental method can evaluate the vibration modal analysis of precision micro slitting turn-milling machine tools to some extent. The experimental modal analysis results guide and optimize the structural design and processing technology of precision micro slitting turn-milling machine tools.


2013 ◽  
Vol 819 ◽  
pp. 76-80 ◽  
Author(s):  
Bo Yang ◽  
Yi Wang ◽  
Wen Li Yu ◽  
Xin Hua Yao ◽  
Jian Zhong Fu

Great efforts have been made to improve the accuracy of NC machine tools, within which thermal error compensation is one of the most efficient ways. A new thermal error compensation instrument which is based on thermal modal analysis for NC machine tools is introduced in this paper. OMRONsCJ2M-CPU11 is used as microcontroller, and SAILING TECHNOLOGYs STA-A08 temperature measuring modules as temperature transmitter. Through hardware and software design, high precision and stability can be achieved. By measuring several key points temperature and making use of a thermal error compensation theory, real-time thermal error compensation can be output to the machine tool, thus thermal error can be reduced.


2012 ◽  
Vol 150 ◽  
pp. 205-210 ◽  
Author(s):  
Long Xue Xiao ◽  
Guo Qing Wu ◽  
Xu Dong Zhang

The structural and working principle of a kind of maglev linear feed unit for CNC engraving and milling machine tools are presented, and its mathematical model is analyzed, then its model of vibration is established in this paper. The modal analysis is made, the natural frequency is calculated with its vibration models, and the influence on the natural frequency of electromagnetic levitation bearing unit, which is caused by stiffness and damping coefficients of electromagnetic levitation bearing, is analyzed respectively by means of ANSYS software. The calculation and analysis presented in this paper can help us design the structure of the maglev linear feed unit for CNC engraving and milling machine tools, and can also establish a solid foundation for further etailed dynamics analysis.


2021 ◽  
Vol 2069 (1) ◽  
pp. 012135
Author(s):  
N D Svane ◽  
A Pranskunas ◽  
L B Lindgren ◽  
R L Jensen

Abstract The architecture, engineering, and construction (AEC) industry experiences a growing need for building performance simulations (BPS) as facilitators in the design process. However, inconsistent modelling practice and varying quality of export/import functions entail error-prone interoperability with IFC and gbXML data formats. Consequently, repeated manual modelling is still necessary. This paper presents a coupling module enabling a semi-automated extract of geometry data from the BIM software Revit and a further translation to a BPS input file using Revit Application Programming Interface (API) and visual programming in Dynamo. The module is tested with three test cases which shows promising results for fast and structured semi-automatic geometry modelling designed to fit today’s practice.


2020 ◽  
Vol 12 (10) ◽  
pp. 168781402096832
Author(s):  
Xuchu Jiang ◽  
Xinyong Mao ◽  
Yingjie Chen ◽  
Caihua Hao

The states of the machine tool, such as the components’ position and the spindle speed, play leading roles in the change of dynamic parameters. However, the traditional modal analysis method that modal parameters manually identified from vibration signal is greatly interfered by harmonics, and the process of eliminating interference is very inefficient and subjective. At present, there is a lack of a standard and efficient method to characterize modal parameter changes in different states of machine tools. This paper proposes a new machine tool modal classification analysis method based on clustering. The characteristics related to the modal parameters are extracted from the response signal in different states, and the clustering results are used to reflect the changes of machine tool modal parameters. After the amplitude of the frequency response function is normalized, the characteristics related to the natural frequency are acquired, and the clustering results further reflect the difference of the natural frequency of the signal. The new method based on clustering can be a standard and efficient method to characterize modal parameter changes in different states of machine tools.


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