Purpose: The paper describes the method and corresponding software used for modelling and vibration analysis of mechanical systems. A s an example the study on the modelling of a vibrating system in a form of a passenger car was discussed with determination of the characteristics describing its vibrations and resonance zones. Design/methodology/approach: The software described in the article uses the matrix hybrid graphs method and matrix block diagrams method for making analysis of mechanical systems vibrations. For numerical calculations the system is represented in the form as a matrix block diagram, and is analysed in detailed way in the MatlabSIMULINK environment. Findings: Numerical software packages give possibility to analyse vibrations of mechanical systems or of their parts exposed to kinematic and dynamic excitations. Research limitations/implications: Time responses of the vibrations of the passenger car system model evoked by various types of excitations are presented, as well as the amplitude –frequency –phase characteristics (a-f-p). Originality/value: The paper constitutes the source of information into the theory and practice of mechanical vibrations as well as professional computer software as a tool enabling the determination of the time responses and the a-f-p characteristics of machine and equipment parts.

Vibration analysis of mechanical systems with utilisation of GRAFSIM and CATGEN software

Guillotine shearing machines for metal sheet may be inadvertently operated at increased blade clearance. Typical cases were studied using commercially available finite element software with an explicit solver. Loads causing elastic deformation to the machine structure arise from plastic deformation of the sheet metal being processed, its behavior being modelled by modified Johnson-Cook law. Excessive clearance was found to overload the machine considerably compared to normal clearance, owing to considerable lateral forces. As a result, the guillotine and much less so the base of the machine, undergo oscillatory deformation and the sheet is partly sheared and mostly bent. Such analysis helps the designer understand structural issues of the machine tool in extreme situations and modify the design appropriately.

https://jacm.scu.ac.ir/article_16072_56f004182042b529623921721d9488b6.pdf

Numerical Analysis of the Deformation of a Shearing Machine Tool under Excessive Blade Clearance

Article history: Received 6 October, 2015 Accepted 23 April 2016 Available online 24 April 2016 Double-sided trimming shear machine is used for longitudinal both–sided trimming of steel plates and simultaneous scraping of trimmed edges at specific length. Side trimming shear (STS) executes the most vital role in increasing the productivity of plate mill and due to its feature, efficiency of plate mill division is enormously increases. In general, frequency of the occurrence of breakdown in STS machine is a most challenging task when STS performs side trimming and scrap cutting machining process. Bhilai Steel Plant (Steel Authority of India at Bhilai) in India is continuously facing a problem due to breakdown of STS machine. The use of separate knife for side trimming and scrap cutting reduces the possibility of scrap jamming which is a major reason for breakdown of STS machine. Researchers and practitioners also suggest the use of arc guillotine shear for side trimming and straight guillotine shear for scrap cutting for minimizing the breakdown in STS machine. The aim of this study is to describe the problems faced by the steel industry as well as the necessary steps which should be taken for improvement of the productivity of STS machine and also it has made contribution to Bhilai Steel Plant by its growth and prosperity. The methodology of study is purely qualitative and the results point out the problems, its implications, steps taken to improve the overall productivity of Bhilai steel plant. © 2016 Growing Science Ltd. All rights reserved.

/pdf/guillotine-side-trimming-shear-machine-a-case-study-of-plate-i5b63z96y2.pdf

Guillotine side trimming shear machine: A case study of plate mill in Bhilai steel plant

Dynamic analysis of two types of over-crank guillotine shears—a comparative study

Engineering analysis of a commercial inclined scrap shear with a cutting force of 1100 tons is given in this study. An analysis model is created in Solidworks (SW). The assembly of the system contains members, which are the frame, two flippers, clamp, and guillotine. There are a revolute joint between the flippers and the frame, a slider joint between the clamp and the frame, and a slider joint between the guillotine and the frame. The free-body diagrams of the members are explored. Multi-body finite element (FE) analysis of the whole assembly is used instead of single-body FE analysis of members. A pin connection is defined for the revolute joint and, no penetration contacts are defined for the slider joints in the multi-body analysis. The fixed boundary condition is defined on the surface of the frame contacting the ground. The moving members are actuated by the fluid power with 300 bars of maximum pressure. The flippers and the clamp press the scrap metal and the guillotine cuts it. The curvature-based mesh is used in FE analysis. The von Mises stresses and deformations are calculated. Smaller mesh sizes are used by using mesh control in the critical regions where high stresses occur to check the stability of the results. Average stress values are considered in the regions where the maximum stress occurs at single finite elements. KeywordFinite element, multi-body, recycling machines, Solidworks

/pdf/multi-body-finite-element-analysis-of-an-inclined-scrap-3a3wvkbab9.pdf

S. Sasikiran

Papers

Dynamic analysis of a guillotine shearing machine