Gary S. Schajer, P.E.
Professor and Assistant Head, Teaching
B.A., M.A. (Cambridge), M.S., Ph.D. (California Berkeley,
Eur. Ing., Member SEM, Member F1MechE, Fellow ASME
ph: (604) 822-6004
fx: (604) 822-2403
email: schajer@mech.ubc.ca
lab website: Renewable Resources Laboratory
Research Interests
- Industrial Residual Stress Measurements
- Laser Holography
- CT Scanning
- Industrial Sensor Design
Current Research Work
- Industrial Residual Stress Measurements
- Residual (or “locked-in”) stresses in engineering components can have a profound effect on service performance, particularly fatigue life. Because of their locked-in nature, residual stresses are difficult to measure, and even more difficult to calculate. This research area is aimed at developing methods for measuring residual stresses that are suitable for industrial use. The work focuses on Electronic Speckle Pattern Interferrometry (ESPI) and on strain-gage techniques.
- Lumber Manufacturing Process Control
- Serious wastage of wood occurs if lumber is not cut accurately in sawmills. The inaccurate wood then has to be planed very deeply to remove the errors. This research involves developing a high-speed scanner that can measure the surface profile of each surface of rapidly moving lumber, independent of any rigid-body motions. The profile measurements can then be used to identify any machining defects and diagnose the needed machine adjustments.
- Particleboard Machining Performance Improvement
- Particleboard is a vesatile wood-based material that can be used to make a wide variety of products, including structural panels, furniture and automotive components. However, the coarse internal texture makes it difficult to achieve a smooth surface finish when the material is cut. The objective of this research is identify the material properties and process conditions that control surface finish. The cutting conditions can then be matched to the material properties to achieve a superior surface quality.
- Enhanced Accuracy Wood Cutting
- This research is aimed at improving industrial methods for assessing and maintaining wood-cutting sawblades to achieve optimal cutting conditions. High accuracy, low-waste wood cutting has substantial economic benefits because raw material accounts for about 70% sawmill cost. It is also desirable environmentally because the reduced wastage increases wood utilization and partially offsets the effects of increasingly limited log supplies.
Selected Publications
- Schajer, G.S. “Hole-Drilling Residual Stress Profiling with Automated Smoothing.” Joural of Engineering and Technology. In press. 2007.
- Schajer, G.S. and Prime, M.B. “Use of Inverse Solutions for Residual Stress Measurements”, Journal of Engineering Materials and Technology, vol.128, no.3, pp.375-382, 2006.
- Schajer, G.S. and Steinzig, M. “Full-field Calculation of Hole Drilling Residual Stresses from Electronic Speckle Pattern Interferometry Data.”, Experimental Mechanics, vol.45, no.6, pp.526-532, 2005.
- Schajer, G.S. and Orhan, F.B. “Microwave Non-Destructive Testing of Wood and Similar Orthotropic Materials”, Subsurface Sensing Technologies and Applications, vol.6, no.4, pp.293-313, 2005.
- Schajer, G.S. and Gazzarri, J.I. “Surface Profiling Using Sequential Sampling and Inverse Methods. Part I: Mathematical Background. Part II: Implementation and Experimental Results”, Experimental Mechanics, vol.44, no.5, pp.473-479 and pp.480-486, 2004.
- Schajer, G.S. “Lumber Strength Grading using X-Ray Scanning”, Forest Products Journal, vol. 51, no. 1, pp. 43-50, 2001.
Recent Awards
- Most Outstanding Mech2 Professor. Mech2 Students, UBC. 2005.
- Teaching Award for Excellence in Engineering and Geoscience Education. Association of Professional Engineers and Geoscientists of British Columbia, 2005.
- Marquardt Wood Engineering Research Award. Forest Products Society. 2004.
- Faculty Recognition Award. UBC Engineering Co-op Education Program, 2004.
