Sampsa Vili Antero LaaksoUniversity of Turku | UTU · Department of Mechanical and Materials Engineering
Sampsa Vili Antero Laakso
Doctor of Science in Technology
About
42
Publications
18,339
Reads
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335
Citations
Citations since 2017
Introduction
Assistant Professor Dr. Sampsa Laakso is a production engineering researcher currently working in University of Turku. His research interests are in the field of metal cutting, especially finite element simulations. His research is focused on material modelling and model parameter acquisition. Other research includes 5-axis machining, ultrasonic burnishing and digital manufacturing.
Additional affiliations
March 2021 - present
Position
- Professor (Assistant)
Description
- Education and research in digital design and manufacturing & industrial collaboration and pedagogical leadership.
September 2019 - March 2021
Position
- Lecturer
Description
- Responsible teacher of several courses, research and coordination of a professional metal cutting education network (MCR) and coordination of professional research network on process fluids (PVC).
September 2018 - September 2019
Education
May 2019 - May 2020
May 2010 - December 2015
September 2004 - December 2009
Helsinki University of Technology
Field of study
- Mechanical Engineering
Publications
Publications (42)
![Table 2 FEM Simulation Error Compared to Experiments [Publication 4]](profile/Sampsa-Laakso/publication/285577282/figure/tbl1/AS:651152140025858@1532258176372/FEM-Simulation-Error-Compared-to-Experiments-Publication-4_Q320.jpg)
Metal cutting is a complex physical problem with many interdependent operational parameters. To illustrate this, a graph analysis is performed for the network of relationships between the parameters. In order to systematically develop metal cutting operations, a tool such as finite element simulations, capable of simultaneously calculating the comb...
Flow stress models in finite element analysis of metal cutting require material parameters that are essential considering the accuracy of the simulations. This article presents a method to acquire material parameters from cutting experiments using the extended Oxley’s shear zone theory. The novelty in this approach is to use measured chip geometry...
Material model parameters are the primary source of error in the finite element analysis (FEM) of cutting processes. Expensive and time consuming material testing is required in order to describe the material's behavior in high temperature and high strain rate conditions during cutting. An alternative approach has been suggested in research papers;...
Results of materials testing for lead-free brass show that the effect of thermal softening decreases significantly when the strain rate is high. This behavior is referred to as thermal softening damping. In this article, a flow stress model with thermal softening damping based on the Johnson–Cook flow stress model was developed. Finite element simu...
Metal cutting fluids for improved cooling and lubrication are an environmental risk and a health risk for workers. Minimizing water consumption in industry is also a goal for a more sustainable production. Therefore, metal cutting emulsions that contain hazardous additives and consume considerable amounts of water are being replaced with more susta...
Metal cutting fluids for improved cooling and lubrication are an environmental risk and a health risk for workers. Minimizing water consumption in industry is also a goal for a more sustainable production. Therefore, metal cutting emulsions that contain hazardous additives and consume considerable amounts of water are being replaced with more susta...
One of the most dominant manufacturing methods in the production of electromechanical devices from sheet metal is punching. In punching, the material undergoes plastic deformation and finally fracture. Punching of an electrical steel sheet causes plastic deformation on the edges of the part, which affects the magnetic properties of the material, i....
Damage models are used in metal cutting simulations to adjust the flow stress and to enable the serrated chip formation and chip breakage. The models describe the rupture strain of the material that is a function of temperature, stress, strain and strain rate. When a damage parameter in the model reaches a critical value, the flow stress of the mat...
Ultrasonic burnishing is attracting ever-greater interest as a surface finishing process. Although the popularity of this method in manufacturing industry remains limited, research is being conducted to explore both the detailed aspects and the limitations of this method. Tangential misalignment is one of most influential parameters in determining...
The purpose was to evaluate part properties of additively manufactured 18Ni-300 maraging steel in a unified set-up when the printing orientation and the heat treatment were independently changed. Though the hardness, shrinkage, and drilling thrust force showed isotropic behavior to a certain extent, anisotropy was observed in the flatness, surface...
Implementing additive manufacturing in an industry, particularly for critical applications of lightweight aluminum (AlSi10Mg), requires part properties that are both accurate and precise to conform to the intent of a robust design. In this experimental study, the objective was to evaluate anisotropy in part properties (i.e., flatness, surface rough...
This study investigates machining superalloy Inconel 718 with polycrystalline cubic boron nitride (pcBN) tooling both numerically and experimentally. Particular attention is given to mechanical and thermal stresses in the cutting tool arising from segmented chip formation and associated forces and temperatures. The temperature dependence of the mec...
Ultrasonic burnishing is a surface finishing process that produces fine surface roughness, improved geometrical accuracy, high compressive residual stresses and increased hardness. The method is suitable for finishing dies or other double curvature surfaces and it does not require changing of the fixturing setup after a machining process. The metho...
Modelling of tool wear in metal cutting processes has been the foundation of the field since the famous Taylor’s tool life model. Tool wear models have been developed for planning machining operations and calculating production costs. Most wear models do not include wear rate in the model but rather just the final wear at end of tool life, i.e. the...
This paper investigates the differences of leaded and low-lead brasses in terms of mechanical and thermal properties, machinability and product strength using physical testing and simulations. The information can be used in companies for Design for Manufacturability (DFM) while designing processes for lead free brass. The novelty of this research i...
This paper investigates the differences of leaded and low-lead brasses in terms of mechanical and thermal properties, machinability and product strength using physical testing and simulations. The information can be used in companies for Design for Manufacturability (DFM) while designing processes for lead free brass. The novelty of this research i...
Underestimated feed force is a known systematic error in cutting simulations. It is considered a consequence of inaccurate friction models, but there are indicators that friction is not the only reason for the error. In some cases, the value of Coulomb friction must be over 1.0 to compensate for the feed force and such values cause over-estimated c...
Contact stress on the tool has been measured with a split-tool apparatus that has a poor resolution of the stress distribution, and with photoelastic tools that cannot be used with real cutting parameters since the materials are too weak. This paper presents an improved split-tool design allowing continuous stress distribution dataset instead of di...
Contact stress on the tool has been measured with a split-tool apparatus that has a poor resolution of the stress distribution, and with photoelastic tools that cannot be used with real cutting parameters since the materials are too weak. This paper presents an improved split-tool design allowing continuous stress distribution dataset instead of di...
This paper presents the development of a FE-simulation model to predict the mechanical stresses and thermal loads that a cutting tool of polycrystalline cubic boron nitride (pcBN) is subjected to, when machining AISI 316L. The serrated chip formation of AISI 316L has a major impact on the periodic loads acting on the cutting tool. Therefore, it is...
Electrical steel is used for the active parts in electrical machinery that form the magnetic circuits because the material experiences low iron loss, and thus, has superior magnetizing properties. A typical electrical sheet has a thickness of 0.5 mm and is punched into its final shape via a piercing process. Piercing causes large deformations and r...
Contact stress on the tool has been measured with a split-tool apparatus that has a poor resolution of the stress distribution, and with photoelastic tools that cannot be used with real cutting parameters since the materials are too weak. This paper presents an improved split-tool design allowing continuous stress distribution dataset instead of di...
The effect of cutting data on the stagnation zone of a machining operation is of great interest since it governs the material flow around the cutting edge. The material flow has a significant influence on the mechanical properties of the machined surface. This paper presents a numerical model that is able to determine the effect that the uncut chip...
Metal cutting simulations have become an important part of cutting tool design and the research in the field in general. One of the most important aspects of modeling is the accuracy of the tool geometry. 3D microscopy is used for measuring the tool edge radius with good accuracy. However, especially with sharp tools, i.e. small tool edge radii, th...
In order to improve the surface quality of TC4 titanium alloy parts, the effect of grinding parameters on surface integrity must be known. In this research, an experimental analysis has been conducted to understand the effect of grinding parameters, including cutting velocity, feed rate, grinding depth and abrasive size, on material removal and sur...
Metal cutting simulations have become an important part of cutting tool design and the research in the field in general. One of the most important aspects of modeling is the accuracy of the tool geometry. 3D microscopy is used for measuring the tool edge radius with good accuracy. However, especially with sharp tools, i.e. small tool edge radii, th...
In order to improve the surface quality of TC4 titanium alloy parts, the effect of grinding parameters on surface integrity must be known. In this research, an experimental analysis has been conducted to understand the effect of grinding parameters, including cutting velocity, feed rate, grinding depth and abrasive size, on material removal and sur...
The goal of metal cutting research is to predict process conditions accurately with a model or a simulation, in order to optimize and develop the processes. Development of such a model requires understanding of multiple branches of physics and engineering such as continuum mechanics, thermodynamics, tribology and materials science. For an accurate...
The demand for good surface quality and good fatigue resistance
of engineering components is becoming ever greater. Mechanical surface
treatments are performed to improve the surface properties and quality of
cylindrical workpieces. In this article, the surfaces produced by two different
surface treatment methods are evaluated in terms of their sur...
The demand for good surface quality and good fatigue resistance of engineering components is becoming ever greater. Mechanical surface treatments are performed to improve the surface properties and quality of cylindrical workpieces. In this article, the surfaces produced by two different surface treatment methods are evaluated in terms of their sur...
Material model parameters are the primary source of error in the finite element analysis (FEM) of cutting processes. Expensive and time consuming material testing is required in order to describe the material's behavior in high temperature and high strain rate conditions during cutting. An alternative approach has been suggested in research papers;...
Electrical steel is used in electrical machinery for the active parts that form the magnetic circuits because the material has low iron loss and thus superior magnetizing properties. A typical electrical sheet has a thickness of 0.5 mm and is punched to a final shape with a piercing process. Piercing causes large deformations and residual stresses...
Survey results of doctoral students conditions in Finnish Universities.
A manual assembly line environment includes a large number of factors that affect the performance of the system. At the moment, these factors and their effects are investigated in separate research papers that relate to different disciplines, and thus there is an increasing need to handle them together. This study contributes to the understanding o...
Poor chip breakage causes problems in machining of low-lead brass. To improve chip breakage, finite element model simulations were implemented in cutting tool design. Finite element model simulations enable high number of experiments that would be expensive and slow to perform by conventional cutting tests. Compression tests and cutting experiments...
Ultrasonic burnishing is a relatively new method used for finishing workpieces to produce good surface quality. Ultrasonic burnishing does not involve material removal from the surface of the workpiece. However, the method has a significant deforming effect on the material, especially close to the surface, which is why it is vital to know the effec...
This study makes a proposal and then presents the information required to describe operations and human resources management factors in a manual assembly line environment. This information is needed since the purpose of this study is to increase the understanding of the effects of the factors and their interrelationship on system performance. Becau...
In this work, the interdependencies of different metal cutting parameters are examined. In order to ensure competitiveness in the field of manufacturing, the quality, productivity and costs of the work must be in optimal balance. The parameters affecting the end result of a metal cutting process form a complex web of interdependencies. In this work...
For the past fifty years metal cutting
researchers have developed many modeling techniques
including analytical techniques, empirical approaches and
finite element techniques. In recent years, the finite
element method has particularly become the main tool for
simulating metal cutting processes. Finite element models
are widely used for calculating...
Questions
Questions (2)
Let's say I have WxWxW block of material that has one free surface and other surfaces are assumed to continue to semi-inifinite, or the actual block is significantly larger than the simulated block. The free surface has boundary condition for heat transfer coefficient set to free convection to air. The initial block will have point like temperature distribution and I need to simulate the temperature after certain period of time.
What boundary conditions should be used to simulate this as semi-inifite block?
I would assume that heat transfer coefficient is set, but to what value? Can it be calculated somehow from the materials heat capacity and thermal conductivity?
Namely, is the rotation of the test specimen supposed to be free or fixed?
I am using the methodology presented in "A Study of Large Plastic Deformation in Dual Phase Steel Using Digital Image Correlation and FE Analysis" by Tarigopula et al. 2007.
Projects
Projects (2)
From the invention of turning machine or lathe, some engineers are trying to increase the turning productivity. The increase of productivity is following after the breakout in instrumental area, such as the hard alloy instrument and resistance to wear cutting surfaces . The potential of cutting speed has a certain limit. New steel marks and cutting surfaces types allow significantly increase cutting and turning speeds. For the most operation types the productivity increase begins from the feeding increase. But the increase of feeding goes together with machined surface result decreasement. Metal cutting with high feeding is one of the most actual problems in the increasing of manufacturing volume but there are some problems one of them is the cutting forces increasement and larger metal removal rate, which decrease the cutting tool life significantly. Increasing of manufacturing volume, going together with the cutting instrument technology and material evolution, such as the invention of the carbide cutting materials and wear resistant coatings such as TiC and Ti(C,N). Each of these coating have its own properties and functions in the metal cutting process. Together with this evolution the cutting tool geometry and machining parameters dependencies are researched. Traditionally for the decreasing the machining time of one part, the cutting parameters were increased, decreasing by this way the machining operation quantity. In our days the wear resistance of the cutting tools increasing and it is mostly used one or two machining operations (medium and fine finishing). The purpose of the topic is to represent the experimental results of the stainless steel turning process, using increased cutting speeds and feeding values, to develop advanced processing technology, using new modern coated cutting tools by CVD and PVD methods. After investigation of the machined surface roughness results, develop the mathematical model of the cutting process using higher values of the cutting parameters.
Metal cutting energy and cost efficiency is investigated through analytical and numerical models to minimize costs, energy consumption or both.
Modeling of contact phenomena in tool-chip interface to better understand friction and tool wear in machining.
