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Cao, P., Zhu, Z., Buck, D., Xiaolei, G., Ekevad, M. & Wang, X. A. (2019). Effect of rake angle on cutting performance during machining of stone-plastic composite material with polycrystalline diamond cutters. Journal of Mechanical Science and Technology, 33(1), 351-356
Open this publication in new window or tab >>Effect of rake angle on cutting performance during machining of stone-plastic composite material with polycrystalline diamond cutters
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2019 (English)In: Journal of Mechanical Science and Technology, ISSN 1738-494X, E-ISSN 1976-3824, Vol. 33, no 1, p. 351-356Article in journal (Refereed) Published
Abstract [en]

This study investigates the effect of rake angle on cutting performance during machining of stone-plastic composite material with diamond cutters. To that end, an orthogonal cutting experiment was designed, in which stone-plastic composite material was planed by a polycrystalline diamond (PCD) cutter to produce chips. The features studied include cutting forces, cutting heat, chip formation and cutting quality. The conclusions are as follows: Firstly, increased rake angle causes frictional force and resulting force to decrease, promoting an increase in normal force. Secondly, during planing, cutting heat is primarily distributed in the chips, with less retained in the cutting edge, and the least retained in the machined surface. The temperatures of both cutting edge and chip decline with an increase in rake angle. Thirdly, as rake angle increases, chip morphology changes from segmental to curved and then to particle chips, with chip-breaking lengths first increasing and then decreasing. Finally, an increased rake angle leads a more stable cutting process and improved cutting quality. Therefore, with the precondition of blade strength, a diamond cutter with a larger rake angle can be used to machine stone-plastic composite to improve production quality by forming a smoother machined surface.

Place, publisher, year, edition, pages
Springer, 2019
Keywords
Orthogonal cutting, PCD blades, Cutting forces, Cutting heat, Cutting quality, Chip formation
National Category
Other Mechanical Engineering
Research subject
Wood Science and Engineering
Identifiers
urn:nbn:se:ltu:diva-72688 (URN)10.1007/s12206-018-1237-y (DOI)000455641100035 ()2-s2.0-85060183090 (Scopus ID)
Note

Validerad;2019;Nivå 2;2019-01-25 (johcin) 

Available from: 2019-01-25 Created: 2019-01-25 Last updated: 2019-02-01Bibliographically approved
Berg, S., Turesson, J., Ekevad, M. & Huber, J. A. (2019). Finite element analysis of bending stiffness for cross-laminated timber with varying board width. Wood Material Science & Engineering
Open this publication in new window or tab >>Finite element analysis of bending stiffness for cross-laminated timber with varying board width
2019 (English)In: Wood Material Science & Engineering, ISSN 1748-0272, E-ISSN 1748-0280Article in journal (Refereed) Epub ahead of print
Abstract [en]

ross laminated timber (CLT) is a wood panelling building system that is used in construction, e.g. for floors, walls and beams. Because of the increased use of CLT, it is important to have accurate simulation models. CLT systems are simulated with one-dimensional and two-dimensional (2D) methods because they are fast and deliver practical results. However, because non-edge-glued panels cannot be modelled under 2D, these results may differ from more accurate calculations in three dimensions (3D). In this investigation, CLT panels with different width-to-thickness ratios for the boards have been simulated using the finite element method. The size of the CLT-panels was 3.0 m × 3.9 m and they had three and five laminate layers oriented 0°–90°–0° and 0°–90°–0°–90°–0°. The thicknesses of the boards were 33.33, 40.0, and 46.5 mm. The CLT panel deformation was compared by using a distributed out-of-plane load. Results showed that panels with narrow boards were less stiff than wide boards for the four-sided support setup. The results also showed that 2D models underestimate the displacement when compared to 3D models. By adjusting the stiffness factor k88, the 2D model displacement became more comparable to the 3D model.

Place, publisher, year, edition, pages
Taylor & Francis, 2019
Keywords
Cross laminated timber, finite element analysis, board width, out-of-plane loading
National Category
Wood Science Other Mechanical Engineering
Research subject
Wood Science and Engineering
Identifiers
urn:nbn:se:ltu:diva-73140 (URN)10.1080/17480272.2019.1587506 (DOI)2-s2.0-85062711678 (Scopus ID)
Available from: 2019-03-08 Created: 2019-03-08 Last updated: 2019-03-20
Zhaolong, Z., Buck, D., Guo, X., Pingxiang, C. & Ekevad, M. (2019). Machinability of stone-plastic materials during diamond planing. Applied Sciences: APPS, 9(7), Article ID 1373.
Open this publication in new window or tab >>Machinability of stone-plastic materials during diamond planing
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2019 (English)In: Applied Sciences: APPS, ISSN 1454-5101, E-ISSN 1454-5101, Vol. 9, no 7, article id 1373Article in journal (Refereed) Published
Abstract [en]

This paper investigated the machinability of a stone–plastic composite (SPC) via orthogonal cutting with diamond cutters. The objective was to determine the effect of cutting depth on its machinability, including cutting forces, heat, chip formation, and cutting quality. Increased cutting depth promoted an increase in both frictional and normal forces, and also had a strong influence on the change in normal force. The cutting temperatures of chips and tool edges showed an increasing trend as cutting depth increased. However, the cutting heat was primarily absorbed by chips, with the balance accumulating in the cutting edge. During chip formation, the highest von Mises strain was mainly found in SPC ahead of the cutting edge, and the SPC to be removed partially passed its elastic limit, eventually forming chips with different shapes. Furthermore, the average surface roughness and the mean peak-to-valley height of machined surfaces all positively correlated to an increase in cutting depth. Finally, with an increase in cutting depth, the chip shape changed from tubular, to ribbon, to arc, to segmental, and finally, to helical chips. This evolution in chip shape reduced the fluctuation in cutting force, improving cutting stability and cutting quality.

Place, publisher, year, edition, pages
Basel, Switzerland: MDPI, 2019
Keywords
composite material; polycrystalline diamond cutter; orthogonal cutting; digital image correlation; DIC analysis; full-field mechanics; machining properties
National Category
Engineering and Technology Other Mechanical Engineering
Research subject
Wood Science and Engineering
Identifiers
urn:nbn:se:ltu:diva-73369 (URN)10.3390/app9071373 (DOI)2-s2.0-85064089350 (Scopus ID)
Note

Validerad;2019;Nivå 1;2019-04-09 (inah)

Available from: 2019-04-01 Created: 2019-04-01 Last updated: 2019-04-24Bibliographically approved
Huber, J. A., Ekevad, M., Girhammar, U. A. & Berg, S. (2018). A Review of Structural Robustness with Focus on Timber Buildings. In: 40th IABSE Symposium: Tomorrow’s Megastructures. Paper presented at 40th IABSE Symposium in Nantes 2018: Tomorrow's Megastructures; Nantes; France; 19 - 21 September 2018. International Association for Bridge and Structural Engineering (IABSE), Article ID S32-17.
Open this publication in new window or tab >>A Review of Structural Robustness with Focus on Timber Buildings
2018 (English)In: 40th IABSE Symposium: Tomorrow’s Megastructures, International Association for Bridge and Structural Engineering (IABSE) , 2018, article id S32-17Conference paper, Published paper (Refereed)
Abstract [en]

With an increasing number of storeys, timber buildings require closer attention to structuralrobustness. If a building can survive unforeseen events (e.g. accidents, terrorism), lives can be saved.The literature appears to be rather limited concerning robustness of timber buildings. This paperaims to give a brief review on robustness in general and design guidelines for timber in specific. Theresults indicate that connection design is a key aspect for robustness. Like in seismic design, by usingthe ductile capacity of connectors, the brittleness of timber can be controlled. For light timber-framebuildings, more guidelines exist than for posts and beams and cross-laminated timber, which bothseem to be similar to steel frames and precast concrete respectively regarding robustness.

Place, publisher, year, edition, pages
International Association for Bridge and Structural Engineering (IABSE), 2018
Keywords
robustness, timber, disproportionate collapse, progressive collapse, alternative load path
National Category
Other Mechanical Engineering
Research subject
Wood Science and Engineering
Identifiers
urn:nbn:se:ltu:diva-70959 (URN)9783857481611 (ISBN)
Conference
40th IABSE Symposium in Nantes 2018: Tomorrow's Megastructures; Nantes; France; 19 - 21 September 2018
Funder
VINNOVA, Bioinnovation 4.4
Available from: 2018-09-24 Created: 2018-09-24 Last updated: 2019-01-14Bibliographically approved
Wei, H., Guo, X., Zhu, Z., Cao, P., Wang, B. & Ekevad, M. (2018). Analysis of Cutting Performance in High Density Fiberboard Milling by Ceramic Cutting Tools. Wood research, 63(3), 455-466
Open this publication in new window or tab >>Analysis of Cutting Performance in High Density Fiberboard Milling by Ceramic Cutting Tools
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2018 (English)In: Wood research, ISSN 1336-4561, Vol. 63, no 3, p. 455-466Article in journal (Refereed) Published
Abstract [en]

In order to study the cutting performance of TiC reinforced Al2O3 ceramic cutting tools in milling high density fiberboard, the effects of cutting parameter on the cutting forces, tool wear and cutting quality were investigated. Under the condition of same average chip thickness, feed per tooth and geometry angles, firstly, the change rate of maximum cutting forces were higher than that of average cutting forces at two different cutting speeds, and the cutting forces at high speed cutting was less than that at low speed cutting. Secondly, the flank wear at high speed cutting was more pronounced than that at low speed cutting, whose abnormal wear were pull-out of grain, cracking, chipping and flanking. Thirdly, the machining quality at high speed cutting was better than that at low speed cutting. Fourthly, the tendencies of cutting forces, tool wear and surface roughness relative to cutting length were similar, but the change rates were different, especially at the initial stage. Finally, high speed cuttingare plausible to use in HDF processing, which not only improves machining quality, but also promotes production efficiency.

Place, publisher, year, edition, pages
Slovak Forest Products Research, 2018
National Category
Other Mechanical Engineering
Research subject
Wood Science and Engineering
Identifiers
urn:nbn:se:ltu:diva-70304 (URN)2-s2.0-85053086508 (Scopus ID)
Note

Validerad;2018;Nivå 2;2018-08-09 (andbra)

Available from: 2018-08-09 Created: 2018-08-09 Last updated: 2018-10-10Bibliographically approved
Huber, J. A., Ekevad, M., Berg, S. & Girhammar, U. A. (2018). Assessment of Connections In Cross-Laminated Timberbuildings Regarding Structural Robustness. In: : . Paper presented at 2018 World Conference on Timber Engineering, Seoul, Republic of Korea, August 20-23 2018.
Open this publication in new window or tab >>Assessment of Connections In Cross-Laminated Timberbuildings Regarding Structural Robustness
2018 (English)Conference paper, Published paper (Refereed)
Abstract [en]

Cross-laminated timber makes timber buildings with an increasing number of storeys achievable. Withmore storeys, structural robustness needs more attention to make a building survive unforeseen events (e.g. accidents,terrorism) and save lives. For steel and concrete buildings, design methods for robustness focus on connection details.The assessment of joints in cross-laminated timber buildings regarding robustness is rather limited in the literature. Theobjective of this paper is to conduct an initial assessment of the connectors after the removal of a wall in a platformcross-laminated timber building. We used the finite element method and the component method for the analysis of acase building. The results indicate that the wall-to-wall and the floor-to-floor connectors may fail at low deflectionlevels leading to high shear loads in the floor panel above the removed wall, which might induce cracking. The removalanalysis was only partially completed, but we identified an indication of the deformation behaviour of the case building.Testing and refined modelling of the connections is needed in the future to verify the results. This study may facilitatefuture investigations regarding robustness of multi-storey cross-laminated timber buildings.

Keywords
Robustness, Connection, Component method, Cross-laminated timber, Finite element method, Disproportionate collapse
National Category
Other Civil Engineering Other Mechanical Engineering
Research subject
Wood Science and Engineering
Identifiers
urn:nbn:se:ltu:diva-70599 (URN)
Conference
2018 World Conference on Timber Engineering, Seoul, Republic of Korea, August 20-23 2018
Projects
Bioinnovation 4.4
Funder
VINNOVA
Available from: 2018-08-27 Created: 2018-08-27 Last updated: 2019-03-27Bibliographically approved
Zhaolong, Z., Buck, D., Ekevad, M., Marklund, B., Guo, X., Cao, P. & Zhu, N. (2018). Cutting forces and chip formation revisited based on orthogonal cutting of Scots pine. Holzforschung, 73(2), 131-138
Open this publication in new window or tab >>Cutting forces and chip formation revisited based on orthogonal cutting of Scots pine
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2018 (English)In: Holzforschung, ISSN 0018-3830, E-ISSN 1437-434X, Vol. 73, no 2, p. 131-138Article in journal (Refereed) Published
Abstract [en]

The objective of this study was to understandbetter the cutting forces and chip formation of Scots pine(Pinus sylvestris L.) with different moisture contents (MCs)and machined in different cutting directions. To thatend, an orthogonal cutting experiment was designed,in which Scots pine was intermittently machined usinga tungsten carbide tool to produce chips. The cuttingforces were measured and the chip shapes were quantitativelydescribed. Four conclusions can be drawn: (1)with increasing MC, the average cutting forces initiallydecreased and then stabilized, while the angle betweenthe direction of the main and the resultant force continuouslydecreased. (2) The average cutting forces in the 90°–0° cutting direction were lower than the same forces inthe 90°–90° cutting direction. (3) During machining, thedynamic cutting forces fluctuated less in the 90°–0° case.However, the dynamic feeding forces showed a decreasingtrend in both the 90°–0° and the 90°–90° cases. (4) Theprocess applied produced granule chips and flow chips,while less curly flow chips with a higher radius of curvaturewere more easily produced from samples with highMCs in the 90°–0° cutting direction.

Place, publisher, year, edition, pages
De Gruyter Open, 2018
Keywords
chip formation, cutting direction, cutting forces, moisture content, tungsten carbide cutting tools, wood machining
National Category
Engineering and Technology Other Mechanical Engineering
Research subject
Wood Science and Engineering
Identifiers
urn:nbn:se:ltu:diva-70662 (URN)10.1515/hf-2018-0037 (DOI)000457473400001 ()2-s2.0-85052992353 (Scopus ID)
Note

Validerad;2019;Nivå 2;2019-02-22 (inah)

Available from: 2018-08-30 Created: 2018-08-30 Last updated: 2019-02-22Bibliographically approved
Zhu, Z., Cao, P., Guo, X., Xie, S. & Ekevad, M. (2018). Cutting performance of cemented carbide cutting tool in turning high‐density fiberboard. Materialwissenschaft und Werkstofftechnik, 49(12), 1476-1484
Open this publication in new window or tab >>Cutting performance of cemented carbide cutting tool in turning high‐density fiberboard
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2018 (English)In: Materialwissenschaft und Werkstofftechnik, ISSN 0933-5137, E-ISSN 1521-4052, Vol. 49, no 12, p. 1476-1484Article in journal (Refereed) Published
Abstract [en]

In order to provide a scientific and reliable guidance for wood processing industry, the effects of cutting parameters on cutting forces, cutting temperature and tool wear were studied when turning high‐density fiberboard by use of cemented‐carbide cutting tools. The results showed that cutting forces (normal force and radial force) and cutting temperature are not affected by the cutting parameters in the same way: cutting forces decrease with increasing spindle speed, whereas cutting temperature increase with an increase of the spindle speed. However, there is a positive relation for cutting forces and temperature, to the feed per turn when cutting. The wear of the cemented‐carbide cutting tool is shown by two mechanisms: Mainly adhesive wear but also abrasive wear, showed by loss of carbide‐grains and by cracking and chipping, respectively. This study also indicated that higher‐speed cutting is beneficial for wood‐processing; evident by reduced energy for cutting and higher efficiency in production.

Place, publisher, year, edition, pages
John Wiley & Sons, 2018
Keywords
High-density fiberboard, cemented carbide cutting tools, cutting forces, cutting temperature, tool wear, Hochdichte Faserplatten, Hartmetall-Schneidwerkzeuge, Schnittkraft, Schnitttemperatur, Werkzeugverschleiß
National Category
Other Mechanical Engineering
Research subject
Wood Science and Engineering
Identifiers
urn:nbn:se:ltu:diva-72492 (URN)10.1002/mawe.201800003 (DOI)000453236700006 ()2-s2.0-85058133353 (Scopus ID)
Note

Validerad;2019;Nivå 2;2019-01-08 (johcin)

Available from: 2019-01-08 Created: 2019-01-08 Last updated: 2019-01-08Bibliographically approved
Li, R., Cao, P., Xu, W., Ekevad, M. & Wang, A. (2018). Experimental and Numerical Study of Moisture-induced Stress Formation in Hexagonal Glulam Using X-ray Computed Tomography and Finite-element Analysis. BioResources, 13(4), 7395-7403
Open this publication in new window or tab >>Experimental and Numerical Study of Moisture-induced Stress Formation in Hexagonal Glulam Using X-ray Computed Tomography and Finite-element Analysis
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2018 (English)In: BioResources, ISSN 1930-2126, E-ISSN 1930-2126, Vol. 13, no 4, p. 7395-7403Article in journal (Refereed) Published
Abstract [en]

Hexagonal glue-laminated timber with large cross-sections, made from small diameter logs, was studied. Effects of relative humidity variations on the moisture-induced stresses were investigated to evaluate how the prediction model compared to a real outcome. The test samples were exposed to an environment with relative humidity variations from 80% to 30%. The moisture content inside the samples was measured via X-ray computed tomography scanning. A moisture transport and a hygromechanical finite element simulation model was used for the prediction of moisture content and resulting stress distribution. The results from both the test and simulation showed that the moisture content in the edge angles of the samples dropped rapidly due to a large moisture diffusion rate. The moisture gradient was generated via a different moisture transfer rate at the inner and external parts of the samples. The maximum stress perpendicular to the grain in the simulation was 8 MPa and was located at the surface near the corners. This stress peak caused cracking according to the model, which was also seen in the test samples. The results for the measured moisture content agreed with the simulated results and this indicated that the moisture transfer model was adequate for simulation.

Place, publisher, year, edition, pages
University of North Carolina Press, 2018
National Category
Other Mechanical Engineering
Research subject
Wood Science and Engineering
Identifiers
urn:nbn:se:ltu:diva-70605 (URN)10.15376/biores.13.4.7395-7403 (DOI)000454215100018 ()
Note

Validerad;2018;Nivå 2;2018-08-27 (andbra)

Available from: 2018-08-27 Created: 2018-08-27 Last updated: 2019-01-29Bibliographically approved
Zhu, Z., Buck, D., Guo, X., Ekevad, M., Pingxiang, C. & Wu, Z. (2018). Machinability investigation in turning of high density fiberboard. PLoS ONE, 13(9), 1-13, Article ID e0203838.
Open this publication in new window or tab >>Machinability investigation in turning of high density fiberboard
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2018 (English)In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 13, no 9, p. 1-13, article id e0203838Article in journal (Refereed) Published
Abstract [en]

A series of experiments were conducted to assess the machinability of high density fiberboardusing cemented carbide cutting tools. The objective of this work was to investigate theinfluence of two cutting parameters, spindle speed and feed per turn, on cutting forces, chipformation and cutting quality. The results are as follows: cutting forces and chip-breakinglength decrease with increasing spindle speed and decreasing feed per turn. In contrast,surface roughness increases with decrease of spindle speed and increase in feed perturn. Chips were divided into four categories based on their shape: dust, particle, splinter,and semicontinuous chips. Chip-breaking length had a similar tendency to the varianceof cutting forces with respect to average roughness and mean peak-to-valley height: anincrease in the variance of cutting forces resulted in increased average roughness andmean peak-to-valley height. Thus, high cutting speed and low feed rate are parameters suitablefor high-quality HDF processing and will improve not only machining quality, but productionefficiency.

Place, publisher, year, edition, pages
Public Library Science, 2018
National Category
Engineering and Technology Other Mechanical Engineering
Research subject
Wood Science and Engineering
Identifiers
urn:nbn:se:ltu:diva-70870 (URN)10.1371/journal.pone.0203838 (DOI)000444545800088 ()30212578 (PubMedID)2-s2.0-85053234275 (Scopus ID)
Note

Validerad;2018;Nivå 2;2018-09-18 (svasva)

Available from: 2018-09-17 Created: 2018-09-17 Last updated: 2018-12-14Bibliographically approved
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ORCID iD: ORCID iD iconorcid.org/0000-0002-0145-080x

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