Author: Valentin Atanasov

Articles

THE INTERNAL FORCES AND STRESSES IN THE BLADE OF A HORIZONTAL BANDSAW AFTER SOLVING THE STATICALLY INDETERMINATE PROBLEM

Authors: Stefan Stefanov, Valentin Atanasov

Summary

The problem of the internal forces and stresses in the blade of a horizontal band-saw is statically indeterminate in the case of pre-tensioning by a spring. After our solution in a preceding article, in this paper the internal forces and stresses in the different parts of the blade are considered. Some remarks are addressed to the interpretation of such stresses in the bandsaw references reviewed. As well, stresses are analyzed relating to bending the blade over the wheel contours. Additional stresses are also outlined: at the guide rollers, other more bending stresses, as well as stresses due to torsion of the blade, etc.

Keywords: horizontal bandsaw blade, spring mechanism, statically indeterminate system, internal forces, stresses

EN Version

RESEARCH ON THE CUTTING OF SPRUCE LOGS IN WINTER CONDITIONS WITH NARROW BAND SAW BLADES

Authors: Zhivko Gochev, Valentin Atanasov

Summary

Experimental researches were performed in winter conditions with a horizontal band saw „Wood-Mizer“ WM 3000. The tests were conducted in manufacturing conditions of the „Chil Tepe – 97“ Ltd. facility in town of Laki by processing spruce logs. Two types of cutting tools were used: with normal and hardened teeth. The results are analyzed and some recommendations are proposed for more efficient use of this machine types.

Keywords: horizontal band saw, narrow band saw blades, frozen wood

EN Version

RESEARCH ON THE QUALITY OF PROCESSED SURFACES WHEN CUTTING SPRUCE LOGS WITH NARROW BAND SAW BLADES

Authors: Valentin Atanasov

Summary

Research on the quality of the processed surfaces was performed with narrow band saw blades in winter conditions. For experiments was used horizontal band saw „Wood – Mizer“ WM 3000. Research was conducted in „Chil Tepe – 97“ Ltd. manufacturing facility in the town of Laki. The cutting tools are with normal and hardened teeth. The results after modification of some technological factors such as feed speed, cutting height and cutting tool operation time are analyzed. Practical recommendations are proposed.

Keywords: horizontal band saw, narrow band saw blades, processed surfaces

EN Version

BANDSAW BLADE STRESS ОF PORTABLE SAWMILLS

Authors: Valentin Atanasov

Summary

Studies have been done for the different stresses acting on the bandsaw blade of portable saw mills. The methods for their determination and their impact on the quality of processed surfaces are analyzed. The relationship between technical parameters of the basic machine units and bandsaw blade are investigated, as well as their impact on the magnitude of stress. The general guidelines for further research in this area are formulated.

Keywords: portable sawmill, band saw blade, stress

BG Version

A MODEL OF THE STATICALLY INDETERMINATE TENSION IN THE BLADE OF A HORIZONTAL BANDSAW

Authors: Stefan Stefanov, Valentin Atanasov

Summary

An original model is proposed for determination of the statically indeterminate tension (internal tensile force) in the blade (saw band) of a horizontal bandsaw with a tensioning spring mechanism. The statically indeterminate problem is solved in a way missing in the bandsaw references but required by the Strength of Materials science: based on a deformation compatibility equation. In the case considered, in that equation the spring parameters are also involved. The model proposed is a generalization of a published previous model (Stefanov 2013) regarding a vertical bandsaw blade tension.

Keywords: bandsaw blade, horizontal bandsaw, spring mechanism, statically indeterminate tension

EN Version

CALCULATION OF OPERATIONAL STRESSES IN BLADES OF HORIZONTAL MOBILE BANDSAWS

Authors: Valentin Atanasov, Stefan Stefanov

Summary

As a continuation of two accompanying papers of ours, in this paper calculation is done relating to operational stresses in blades of horizontal mobile bandsaws as a part of their operational characteristics. In the case of tensioning the blade by a spring mechanism, when the problem of the tensile forces and stresses is statically indeterminate, our solution (from the first accompanying paper) applies. This requires iterations which are programmed in an excel-file. In it, a number of formulas for stress calculation are programmed which are derived in our second accompanying paper. Several types of stress-components, and stress conditions, are involved. A series of additional computational results are obtained automatically with varying the input data in the excel-file. Stress oscillograms have been drawn, as well. They show that, under equal other conditions, the horizontal bandsaw blade is more threatened by fatigue than a vertical bandsaw blade.

Keywords: bandsaw blades, horizontal mobile bandsaws, operational tensile forces and stresses in saw bands, automation of stress calculations

EN Version