Forest Products Mechanics (6 Ects / 4ov) 3513055

Puutuotteiden mekaniikka

Petri P. Kärenlampi

Lectures 26 h, Exercises 74 h, literature and examinations 60 h

Essentials: Strain. Stress. Stress-strain relations. Transformations. Time-dependent mechanical behavior. Moisture and temperature effects.

Complementary knowledge: Irrecoverable deformations. Energy dissipation. The fracture energy.

Special knowledge: Brittleness. Strain-softening.

Student will gain ability to analyze, evaluate and develop mechanical behavior of structures, in particular those made of porous, anisotropic, hygroscopic and time-dependent materials.

Lectures 26 hours:

Monday, Wednesday, Room Bor101

11.9. 2023 8-10 Normal Strain

Normal Stress

Stress-Strain Relations

13.9. 8-12 Volumetric Strain

Shear Strain

Shear Stress

Multiaxial Stress and Strain States

Off-Axis Stress and Strain

Stress and Strain Transformations

18.9. 8-10 Time-Dependent Mechanical Behavior

20.9. 8-12 Moisture and Temperature Effects

Time-Temperature-Moisture-Specific Volume – Equivalency

25.9. 8-10 Irrecoverable Deformations

27.9. 8-12 Yield Criterion

2.10. 8-10 Strength of Materials

The Fracture Energy

4.10. 8-12 Brittleness and Strain-Softening

9.10. 8-10 Wood Products Applications

11.10. 8-12 Pulping Applications

Paper and Paperboard Applications

Lectures will be given at Bor101, and streamed with Video Conference Apparatus into Microsoft Teams. Presently, there are no restrictions to presence in the lecture room. Any participant shall have an opportunity to present questions and comments either in the lecture room or within the Teams-meeting.

Exam will be on site. Please check the exam dates proposed below. Let the lecturer know if there is any time conflict.

Lectures on Mondays can be joined at

https://teams.microsoft.com/l/meetup-join/19%3ameeting_MThiMTNlMTktM2RkOS00ZWQ1LWJmZmMtYmQwMzhjNjQ5MzVi%40thread.v2/0?context=%7b%22Tid%22%3a%2287879f2e-7304-4bf2-baf2-63e7f83f3c34%22%2c%22Oid%22%3a%228457a000-0a53-4a4c-bf47-2814d5d7539c%22%7d

Lectures on Wednesdays can be joined at

https://teams.microsoft.com/l/meetup-join/19%3ameeting_NGQ0M2ZiZWItNGQwNS00N2U2LTk4YmItMTU0MTE2YWEyMTY1%40thread.v2/0?context=%7b%22Tid%22%3a%2287879f2e-7304-4bf2-baf2-63e7f83f3c34%22%2c%22Oid%22%3a%228457a000-0a53-4a4c-bf47-2814d5d7539c%22%7d

Grading:

Weekly exercises 25%

Exam 75%

There are three types of exercises.

Firstly, there are weekly exercises. Then, there is an experimental exercise. And finally, there is a project exercise, where each student presents a forest products application of Mechanics.

Weekly exercises are due each Monday at 9 am, between September 18 and October 9, to be returned to the green metallic mailbox by the main entrance of the Borealis Building.

Experimental exercise September 29.

Reporting Sessions for Experimental exercise on October 13th (Room Bor100), at 12-16.

Project exercise September-October.

Course Literature:

Tsai, S. W. and Hahn, H. T., Introduction to composite materials. Technomic Publishing Co., Westport, CT, 1980, pp. 1-113.

Simo, J. C. and Hughes, T. J. R., Computational inelasticity. Interdisciplinary applied mathematics, Springer Verlag 1998, pp. 1-70.

Smith, T. L., Stress-strain-time-temperature relationship for polymers. ASTM Materials Sci. Series 3, STP-325. American Society of Testing and Materials, New York, NY, 1962, pp. 60-89.

Anderson, T. L., Fracture Mechanics: Fundamentals and Applications. CRC Press, Boca Raton, Florida, 2. ed. 1995, pp. 1-99.

Handwritten lecture notes

Final examination October 16, at 12-14, Room Bor101.

Possibility for eventual renewals October 30 at 12-14, Room Bor100.

Exercises Contents:

There are three types of exercises:

1.Weekly exercises

As explained above. The approximated time consumption is 37 hours.

Exercise 1

Exercise 2

Exercise 3

Exercise 4

Lecture recordings 

https://uef.cloud.panopto.eu/Panopto/Pages/Viewer.aspx?id=5bb75ced-34a1-4b78-9ab3-b07a00ba7701

https://uef.cloud.panopto.eu/Panopto/Pages/Viewer.aspx?id=7fadded6-fb09-4ba8-baf2-b07c00ab555c

https://uef.cloud.panopto.eu/Panopto/Pages/Viewer.aspx?id=1cc2f6cd-7c06-43fd-a202-b07c00ab5524

https://uef.cloud.panopto.eu/Panopto/Pages/Viewer.aspx?id=8350b0ec-685e-4b83-827e-b084005a9880

https://uef.cloud.panopto.eu/Panopto/Pages/Viewer.aspx?id=9420828d-4ad9-4930-b0ca-b084005a985e

https://uef.cloud.panopto.eu/Panopto/Pages/Viewer.aspx?id=79489194-13bf-4a7b-9134-b09a00b6b382

https://uef.cloud.panopto.eu/Panopto/Pages/Viewer.aspx?id=2bfe26c6-b0a1-4dd1-8f00-b08c005a213f

https://uef.cloud.panopto.eu/Panopto/Pages/Viewer.aspx?id=14d6615b-f444-4b5f-ad7a-b08c005a20e9

https://uef.cloud.panopto.eu/Panopto/Pages/Viewer.aspx?id=80bf3922-2adc-479d-8418-b09200d85944

https://uef.cloud.panopto.eu/Panopto/Pages/Viewer.aspx?id=62f19d12-e3b6-402c-9578-b09200d8591b

https://uef.cloud.panopto.eu/Panopto/Pages/Viewer.aspx?id=62f19d12-e3b6-402c-9578-b09200d8591b

2. Implementation and analysis of mechanical experiments

The approximated time consumption of this exercise is 24 hours, of which 2 hours in implementation of the experiment, and 22 hours for analyzing the results.

Briefly, the exercises contain

Experimental determination of:

Small-Strain Stiffness

Stress-Strain Curve

Tangential Stiffness

Irrecoverable Strain

Thermal expansion

Large-Strain Stiffness

Energy Dissipation

The effect of the following factors on the characteristics above

will be investigated:

Moisture Content

Straining Rate

3. Presentation of an application of mechanics in the Forest Products Industry

The approximated time consumption of this exercise is 13 hours, which is budgeted for the study of an application, on the basis of literature, and the preparation of a presentation regarding it. The presentations (each of duration 20...30 minutes, followed by discussion) will be given during the three last sessions of the lecture program.

Any presentation of application is supposed to based in documents identified by the instructor. The title of the presentation is to be designed by the presenter. The following literature is to be used as a basis of presentations. Any participant may choose one of the following groups of references:

A/

3211. Brebner, K. I., Schneider, M. H. and St-Pierre, L. E., Flexural strength of polymer-impregnated eastern white pine. For. Prod. J. 35(2):22-27 (1985).

3210. Brebner, K. I., Schneider, M. H. and Jones, R. T., The influence of moisture content on the flexural strength of styrene-polymerized wood. For. Prod. J. 38(4):55-58 (1988).

3217. Schneider, M. H., Phillips, J. G., Tingley, D. A. and Brebner, K. I., Mechanical properties of polymer-impregnated sugar maple. For. Prod. J. 40(1):37-41 (1990).

3215. Schneider, M. H., Brebner, K. I. and Hartley, I. D., Swelling of a cell lumen filled and cell-wall bulked wood polymer composite in water. Wood Fiber Sci. 23(2):165-172 (1991).

B/

3845. English, B. W. and Falk, R. H., Factors that affect the application of woodfiber-plastic composites. In Proceedings: "Woodfiber-plastic composites: virgin and recycled wood fiber and polymers for composites", May 1-3, 1995, Madison, Wisc., pp. 189-194. Forest Products Society, Madison, Wisc.

3852. Kortschot, M. T., Engineering design and materials seclection: principles and applications for woodfiber-polymer composites. Fourth International Conference on Woodfiber-Plastic Composites, May 12-14, 1997, Madison, Wisc., pp. 113-116. Forest Products Society, Madison, Wisc.

C/

3835. Simonsen, J., The mechanical properties of woodfiber-plastic composites: theoretical vs. experimental. In Proceedings: "Woodfiber-plastic composites: virgin and recycled wood fiber and polymers for composites", May 1-3, 1995, Madison, Wisc., pp. 47-55. Forest Products Society, Madison, Wisc.

3854. Maiti, S. N., Wood flour-polypropylene composites: structure-property relationships. Fourth International Conference on Woodfiber-Plastic Composites, May 12-14, 1997, Madison, Wisc., p. 133. Forest Products Society, Madison, Wisc.

3866. Selke, S. E. and Childress, J., Wood fiber/high-density polyethylene composites: ability of additives to enhance mechanical properties. In:"Wood-Fiber/Polymer Composites: Fundamental Concepts, Processes, and Material Options", Ed. M. P. Wolcott. Forest Products Society, Madison, Wisc. 1993, pp. 109-111.

D/

4495. Stamm, A. J., Burr, H. K. and Kline, A. A., Staybwood – a heat stabilized wood. Ind. Eng. Chem. 38(6):630-634 (1946).

4498. Stamm, A. J.,Thermal degradation of wood and cellulose. Ind. Eng. Chem. 48:413-417 (1956).

4499. Stamm, A. J. and Baechler, R. H., Decay resistance and dimensional stability of five modified woods. Forest Prod. J. 10:22-26 (1960).

4496. Hillis, W. E., High temperature and chemical effects on wood stability. Wood Sci. Tech.18:281-293 (1984).

4487. Santos, J. A., Mechanical behaviour of Eucalyptus wood modified by heat. Wood Sci. Tech. 34(1):39-43 (2000).

4315. Kamdem, D. P., Pizzi, A. and Jermannaud, A., Durability of heat-treated wood. Holz als Roh- un Werkstoff 60(1):1-6 (2002).

4489. Thermowood. Finnish thermowood association.

http://www.thermowood.fi/pdf/thermowood_english.pdf

E/

4490. Inoue, M., Norimoto, M., Tanahashi, M. and Rowell, R. M., Steam of heat fixation of compressed wood. Wood Fiber Sci. 25:224-235 (1993).

4491. Ito, Y., Tanahashi, M., Shigematsu, M., Shinoda, Y. and C. Ohta, C., Compressive-Molding of wood by high-pressure steam-treatment: Part 1. Development of compressively molded squares from thinnings. Holzforschung 52:211-216 (1998).

4492. Ito, Y., Tanahashi, M., Shigematsu, M. and Shinoda, Y., Compressive-molding of wood by high-pressure steam-treatment: Part 2. Mechanism of permanent fixation. Holzforschung 52:217-221 (1998).

4103. Tanahashi, M., Kyomori, K., Shigematsu, M. and Onwona-Agyeman, S., Development of compressive molding process of wood by high-pressure steam and mechanism of permanent fixation for transformed shape. Fist International Conference of the European Society of Wood Mechanics, April 19-21, 2001, Lausanne, Swizerland, pp. 523-531.

4104. Heger, F., Girardet, F., Moeckli, P. and Navi, P., Thermo-hydro-mechanical demsification and influence of post-treatment on set-recovery. Fist International Conference of the European Society of Wood Mechanics, April 19-21, 2001, Lausanne, Swizerland, pp. 493-502.

F/

4466. Wallström, L., Lindberg, K. A. H. and Johansson, I., Wood surface stabilization. Holz als Roh- und Werkstoff 53:87-92 (1995).

4467. Wallström, L., and Lindberg, K. A. H., Wood surface stabilization with polyethylene glycol, PEG. Wood Sci. Tech. 29:109-119 (1995).

4465. Wallström, L., and Lindberg, K. A. H., Measurement of cell wall penetration in wood of water-based chemicals using SEM/EDS and STEM/I. Wood Sci. Tech. 33(2):111-122 (1999).

G/

4386. Kifetew, G.,Thuvander, F., Berglund, L. A. and Lindberg, H., The effect of drying on wood fracture surfaces from specimens tested in wet condition, Wood Sci. Tech. 32(2):83-94 (1998).

4034. Thuvander, F., Wallström, L., Berglund, L. A. and Lindberg, K. A. H., Effects of an impregnation procedure for prevention of wood cell wall damage due to drying. Wood Sci. Tech. 34(6):473-480 (2001).

H/

3512. Björkqvist, T., Menetelmä ja laite puun mekaaniseksi kuiduttamiseksi. Förfarande och anordning för mekanisk defibrering av trä. Finnish Patent 98148 (1995). WO9638624: Method and apparatus for mechanical defibration of wood, published 1996-12-05.

4230. Björkqvist, T. and Lucander, M., Grinding surface with an energy-efficient profile. 2001 International Mechanical Pulping Conference, Helsinki, Finland, June 4-8, 2001, pp. 373-380.

I/

4473. Kärenlampi, P. P., Tynjälä, P. and Ström, P.: Molecular fatigue in cell walls. 2002 Paper Physics Seminar, Finger Lakes, NY, Sept. 8-13, pp. 240-243

4377. Kärenlampi, P. P., Tynjälä, P. and Ström, P., Molecular reorganization in wood. Mechanics of Materials 35(12):1149-1159 (2003).

4322. Kärenlampi, P. P., Tynjälä, P. and Ström, P., Molecular fatigue in steamed wood. Int. J. Fatigue 25(6):489-497 (2003).

4249. Kärenlampi, P. P., Tynjälä, P. and Ström, P., Off-axis fatigue loading of steamed wood. Int. J. Fatigue 24(12):1235-1242 (2002).

J/

2623. Östlund, S., Niskanen, K. and Kärenlampi, P., On the prediction of the strength of paper structures with a flaw. J. Pulp Paper Sci. 25(10):353-360 (1999).

K/

3579. Östlund, S. and Kärenlampi, P., Structural geometry effect on the size-scaling of strength. Int. J. Fract. 109(2):141-151 (2001).

L/

2661. Tryding, J. and Gustafsson, P. J., Characterisation of tensile fracture properties of paper. Tappi 83(2):84-89 (2000).

3622. Tryding, J. and Gustafsson, P. J., Analysis of notched newsprint sheet in mode I fracture. J. Pulp Paper Sci. 27(3):103-109 (2001).

M/

3342. Uesaka, T. and Ferahi, M., Principal factors controlling press room breaks. 1999 Paper Physics Conference, San Diego, CA, Sept. 26-30, 1999, pp. 229-245.

4486. Uesaka, T., Ferahi, M., Hristopulos, D., Deng, N. and Moss, C., Factors controlling press room runnability of paper . 12th Fundamental Research Symposium, Oxford, England, Sept. 2001 (Ed. C.F. Baker), Vol. 2, Ch. 8pp. 1423-1440.

4452. Hristopoulos, D. T. and Uesaka, T., Model of machine-direction web dynamics and impact on web brake rates. PPP2002, Progress in Paper Physics Seminar, Finger Lakes / Syracuse, NY, Sept. 8-13, 2002, pp. 206-209.

N/

3362. Wahlström, T., Adolfsson, K., Östlund, S. and Fellers, C., Numerical modeling of the cross direction shrinkage profile in a dryer section. A first approach. 1999 Paper Physics Conference, San Diego, CA, Sept. 26-30, 1999, p. 517-531.

O/

2976. Glynn, P., Jones, H. W. H. and Gallay, W., The fundamentals of curl in paper. Pulp Paper Can. 60(19):T316-323 (1959).

2973. Gray, D. G., Chirality and curl in paper sheets. J. Pulp Paper Sci. 15(3):J105-109 (1989).

4458. Östlund, M., Östlund, Ö., Carlsson, L. A. and Fellers, C., Experimental determination of residual stresses in paperboard. PPP2002, Progress in Paper Physics Seminar, Finger Lakes / Syracuse, NY, Sept. 8-13, 2002, pp. 180-183..

4443. Persson, M. and Wahlström, T., The development of moisture gradients using different stategies and their influence on process-induced curl. PPP2002, Progress in Paper Physics Seminar, Finger Lakes / Syracuse, NY, Sept. 8-13, 2002, pp. 131-135.

P/

4841. Stanzl-Tschegg, S. E., Microstructure and fracture mechanical response of wood. Int. J. Fract. 139:495-508 (2006).