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Mahdi Eynian

Universitetslektor

Anställd på Avdelningen för avverkande och additiva tillverkningsprocesser.

Forskar inom området teknik, produktionsteknik.


Forskningsområde/forskningsintresse

Min forskning fokuserar på att förbättra bearbetningskvaliteten genom att undvika vibrationer. Särskilt studerar jag vibrationsinstabilitet i skärande bearbetning, så kallat "Chatter". Jag har arbetat med modellering av chatter i radiepinnfräsning och modellering av dämpningen i skärprocessen. Ett annat intressant område för mig är användningen av sensorer och mätmetoder för att studera bearbetningskvalitet. Jag studerar också metoder för mätning och förbättring strukturernas dynamiska styvhet. Dynamisk styvhet hos en struktur beror på dess geometri och materialegenskaper samt dess flexibilitet och friktion på kontaktytor i strukturen, och kan förbättras genom att förändringar i dessa faktorer.

Undervisning/handledning

Jag undervisar kurser i materialvetenskap och skärande bearbetning som ingår i Högskolan västs magister program i produktionsteknik. Jag har också deltagit i undervisning av kurser på grundnivå i finita elementmetoden, robotkinematik och tillverkningsteknik.

Nyckelord

Skärande bearbetning, Dynamiska skärkrafter, Dämpningen i skärprocessen, vibrationer vid skärande bearbetning (Chatter), Strukturdynamik.

Publikationer


A modified johnson-cook model for ferritic-pearlitic steel in dynamic strain aging regime

Publicerat

A modified johnson-cook model for ferritic-pearlitic steel in dynamic strain aging regime

In this study, the flow stress behavior of ferritic-pearlitic steel (C45E steel) is investigated through isothermal compression testing at differen...

Dynamic effects on cutting forces with highly positive versus highly negative cutting edge geometries

Publicerat

Dynamic effects on cutting forces with highly positive versus highly negative cutting edge geometries

Understanding the influence of the cutting edge geometry on the development of cutting forces during the milling process is of high importance in...

Experimental analysis of cutting edge effects on vibrations in end milling

Publicerat

Experimental analysis of cutting edge effects on vibrations in end milling

The ability to minimize vibrations in milling by the selection of cutting edge geometry and appropriate cutting conditions is an important asset in...

In-process identification of modal parameters using dimensionless relationships in milling chatter

Publicerat

In-process identification of modal parameters using dimensionless relationships in milling chatter

Machining parameters needed for stable, high-performance high-speed machining could be found using mathematical models that need accurate...

New methods for in-process identification of modal parameters in milling

Publicerat

New methods for in-process identification of modal parameters in milling

Chatter vibrations encountered in machining can degrade surface finish and damage the machining hardware. Since chatter originates from unstable...

Effect of tool wear on quality in drilling of titaniumalloy Ti6Al4V, Part I : Cutting Forces, BurrFormation, Surface Quality and Defects

Publicerat

Effect of tool wear on quality in drilling of titaniumalloy Ti6Al4V, Part I : Cutting Forces, BurrFormation, Surface Quality and Defects

Titanium's Ti6Al4V, alloy is an important material with a wide range of applications in the aerospace industry.Due to its high strength, machining...

Effect of tool wear on quality in drilling of titaniumalloy Ti6Al4V, Part II : Microstructure and Microhardness

Publicerat

Effect of tool wear on quality in drilling of titaniumalloy Ti6Al4V, Part II : Microstructure and Microhardness

Drilling of Ti6Al4V with worn tools can introduce superficial and easily measured features such as increase of cutting forces, entry and exit burrs...

Finite Element Modeling and Validation of Chip Segmentation in Machining of AISI 1045 Steel

Publicerat

Finite Element Modeling and Validation of Chip Segmentation in Machining of AISI 1045 Steel

The finite element (FE) method based modeling of chip formation in machining provides the ability to predict output parameters like cutting forces...

Influence of radial depth of cut on entry conditions and dynamics in face milling application

Publicerat

Influence of radial depth of cut on entry conditions and dynamics in face milling application

The choice of milling cutter geometry and appropriate cutting data for certain milling application is of vital importance for successful machining...

Sound Analysis in Drilling, Frequency and Time Domains

Publicerat

Sound Analysis in Drilling, Frequency and Time Domains

This paper proposes a guideline for interpreting frequency content and time history of sound measurements in metal drilling processes. Different...

Time Domain Simulation of Chatter Vibrations in Indexable Drills

Publicerat

Time Domain Simulation of Chatter Vibrations in Indexable Drills

Regenerative chatter vibrations are common in drilling processes. These unwanted vibrations lead to considerable noise levels, damage the quality o...

Influence of cutting edge geometry on force build-up process in intermittent turning

Publicerat

Influence of cutting edge geometry on force build-up process in intermittent turning

In the intermittent turning and milling processes, during the entry phase the cutting edges are subjected to high impact loads that can give rise t...

Influence of radial depth of cut on dynamics of face milling application

Publicerat

Influence of radial depth of cut on dynamics of face milling application

The choice of milling cutter geometry and appropriate cutting data for certain milling application is of vital importance for successful machining...

Selection of chatter-free milling conditions using vibration frequency measurements

Publicerat

Selection of chatter-free milling conditions using vibration frequency measurements

Unwanted vibration of the tool with respect to the workpiece, known as chatter, can damage machine tool, cutting tool, and the surface finish of th...

Sensitivity of Axis Tracking Errors of Machine Tools to Tool Wear in Drilling

Publicerat

Sensitivity of Axis Tracking Errors of Machine Tools to Tool Wear in Drilling

Axis Tracking Errors (ATEs) of the active and inactive axis of numerically controlled machine tools are presented as new means of detection of tool...

Prediction of vibration frequencies in milling using modified Nyquist method

Publicerat

Prediction of vibration frequencies in milling using modified Nyquist method

Study of the vibration frequencies at different cutting conditions is an alternative to the use of impact hammer test for identification of natural...

Time-Domain Modeling of Torsional-Axial Chatter Vibrations in Indexable Drills with Low Damping

Publicerat

Time-Domain Modeling of Torsional-Axial Chatter Vibrations in Indexable Drills with Low Damping

Vibration frequencies in stable and unstable milling

Publicerat

Vibration frequencies in stable and unstable milling

Vibration frequencies in machining may be employed for calculation of natural frequencies of the dominant modes in chatter and selection of...

A Mechanistic Approach to Model Cutting Forces in Drilling with Indexable Inserts

Publicerat

A Mechanistic Approach to Model Cutting Forces in Drilling with Indexable Inserts

Holes are made in many industrial parts that need screws, pins or channels for passing fluids. The general method to produce holes in metal cutting...

Frequency Domain Study of Vibrations above and under Stability Lobes in Machining Systems

Publicerat

Frequency Domain Study of Vibrations above and under Stability Lobes in Machining Systems

Using modified Nyquist contours, the dominant poles of the closed loop delay-differential equation for machining systems such as milling are...

Analytical Stability Prediction in Five Axis Ball-End Milling

Publicerat

Analytical Stability Prediction in Five Axis Ball-End Milling

In five axis ball-end milling, the cutting edge is a continuous curve and the engagement with workpiece changes as the cutting tool rotates....

Effect of thin viscoelastic material treatments of the clamping region on dynamic stiffness of the cantilever beams

Publicerat

Effect of thin viscoelastic material treatments of the clamping region on dynamic stiffness of the cantilever beams

Cantilever beams and similar structures are found in machining systems. Often a set of cantilever beams attached to each other on spindle-tool hold...

Cutter Exit Effects during Milling of Thin-walled Inconel 718

Publicerat

Cutter Exit Effects during Milling of Thin-walled Inconel 718

During milling of thin-walled components, chatter vibrations give rise to process issues. These include dimensional inaccuracy, damaged and scrap...

Milling Strategies for Thin-walled Components

Publicerat

Milling Strategies for Thin-walled Components

Recent developments in the Aerospace industry have led to thin-walled, reduced-weight engine designs. Due to demands in manufacturing, production...

Minimization of chatter in machining by the use of mobile platform technologies

Publicerat

Minimization of chatter in machining by the use of mobile platform technologies

Process Stability Strategies in Milling of Thin-walled Inconel 718

Publicerat

Process Stability Strategies in Milling of Thin-walled Inconel 718

Trends in Aerospace development have led to thin-walled, reduced-weight engine designs. The demands in manufacturing have forced production speeds...

Process Stability Strategies in Milling of Thin-walled Inconel 718

Publicerat

Process Stability Strategies in Milling of Thin-walled Inconel 718

Trends in Aerospace development have led to thin-walled, reduced-weight engine designs. The demands in manufacturing have forced production speeds...

Analytical Chatter Stability of Milling With Rotating Cutter Dynamics at Process Damping Speeds

Publicerat

Analytical Chatter Stability of Milling With Rotating Cutter Dynamics at Process Damping Speeds

Thispaper presents a chatter stability prediction method for milling flexibleworkpiece with end mills having asymmetric structural dynamics. The...

Forskningsprojekt