SEARCH

SEARCH BY CITATION

Keywords:

  • snowboard designs;
  • bending and torsional stiffness;
  • camber properties;
  • temperature response

Abstract

  1. Top of page
  2. Abstract
  3. 1. INTRODUCTION
  4. 2. EXPERIMENTAL INVESTIGATION
  5. 3. RESULTS
  6. 4. DISCUSSION
  7. 5. CONCLUSION
  8. REFERENCES

Snowboarding is a weather-dependent sport, where riders may be exposed to considerable changes in on-snow temperature within a short period of time. Anecdotal evidence indicates that such changes affect snowboard performance. The aim of this study was to determine the effect of temperature variations on snowboard stiffness and camber properties, which have been determined in previous research to strongly influence on-snow feel and response. In order to examine this phenomenon in greater detail, three snowboards possessing different composite structures were tested. Each board was subjected to static bending and torsional deflection under standard loads and had their camber measured at 22°C, 4°C and −17°C. The resulting bending and torsional stiffness profiles displayed an increase in overall stiffness with a decrease in temperature, but with negligible stiffness gain occurring between 4°C and −17°C. The camber levels measured at each of these temperatures also exhibited similar trends. The article describes the experimental methods, test results, and the reasons for changes in board stiffness and camber with decreasing temperature. The importance of this research in the structural and vibrational analysis of snowboards is discussed. © 2009 John Wiley and Sons Asia Pte Ltd


1. INTRODUCTION

  1. Top of page
  2. Abstract
  3. 1. INTRODUCTION
  4. 2. EXPERIMENTAL INVESTIGATION
  5. 3. RESULTS
  6. 4. DISCUSSION
  7. 5. CONCLUSION
  8. REFERENCES

The on-snow temperature in snowboarding is highly variable and dependent on factors such as geographical location, elevation, time of year, humidity, wind speed, cloud cover and even time of day. For example, at the height of winter in Canada, riders may be exposed to on-snow temperatures in the order of −20°C. Conversely, as the ski season draws to a close in Australia, the snow will be softened by ambient temperatures slightly above 0°C. To date, there have been no published attempts to fully evaluate the effects of such a temperature change on snowboard properties. This phenomenon should not only be taken into consideration in the overall snowboard design process, but also any post-manufacture laboratory or on-snow analysis. The aim of this study was to determine the effect of temperature variation on snowboard stiffness and camber1 properties, which have been determined from prior research to be directly related to on-snow feel and performance 1, 2. Changes in these key design parameters are related to the temperature dependent properties of the materials used in the snowboards.

Prior studies have investigated the effects of temperature change on composite sandwich structures, although none were directly related to snowboards. Kumar et al. 3 investigated loading rate effects on the mechanical properties of composites at low temperatures. They determined that the differences in response were possibly a result of low-temperature hardening, matrix cracking, misfit strain due to different thermal coefficients of the constituent phases or enhanced mechanical keying by compressive residual stresses at low temperatures. Soni et al. 4 also investigated fatigue at low temperatures and by comparing this phenomenon at room temperature found an increase in stiffness and useful fatigue life, but also an increase in brittleness. An increase in tension and compression strength and elastic moduli of reinforced epoxy fiberglass composites at low temperatures was determined by Walsh et al. 5.

However, there have been several studies investigating the effect of composite construction on resulting snowboard properties. Borsellino et al. 6 focused on the effects of different core materials and polymeric base surfaces. They undertook wettability and adhesion tests for several base materials, where ultra-high molecular weight polyethylene (UHMWPE) exhibited the best mechanical performance. The study also investigated the effect of using wood, PVC and polymer foam cores on the bending and torsional flexural properties of the sandwich composite structure. They determined that in wood core structures, the core plays a large role in the properties of the final composite. Conversely, they found that a low density polymer foam core merely acts as a support for the fiberglass layers and to separate them from the neutral axis. Grewal et al. 7 investigated the effect of different snowboard constructions on stiffness, strength and work energy to failure. The study determined that stiffness and strength were more strongly influenced by the core wrap thickness and not the core material, whereas stored work energy was more closely related to the core material and construction method. Neither of these studies however obtained complete bending and torsional stiffness distributions for any snowboard models (Borsellino et al. only tested small composite samples to use in a Finite Element Analysis model), nor considered the effect of temperature in their analysis.

This research aimed to provide a deeper understanding of the key snowboard design parameters, and determine how sensitive they are to common on-snow temperature variations. Complete bending and torsional stiffness distributions and camber properties have been obtained at temperatures (22°C, 4°C and 17°C) for three test snowboards with different composite sandwich structures. The article presents a detailed description of the experimental methodology utilized, and a comprehensive analysis and discussion of the temperature dependent stiffness and camber properties.

2. EXPERIMENTAL INVESTIGATION

  1. Top of page
  2. Abstract
  3. 1. INTRODUCTION
  4. 2. EXPERIMENTAL INVESTIGATION
  5. 3. RESULTS
  6. 4. DISCUSSION
  7. 5. CONCLUSION
  8. REFERENCES

In order to evaluate the general effects of temperature on snowboard stiffness and camber properties, a sample group of snowboards spanning the freeride and freestyle riding styles was selected for testing. One predominantly freeride and one specialist freestyle snowboard were chosen to represent the extremes of the style spectrum, and a third versatile snowboard was selected mid-way. The snowboards possessed significantly different composite constructions, varying with core material, layer composition and base material. Table 1 shows detailed specifications of the test boards, while Figures 1–3 illustrate the general composite structure of a snowboard and types of fiberglass fabric.

thumbnail image

Figure 1. General snowboard structure (© 2009 Woodhead Publishing Ltd. Reproduced with kind permission).

Download figure to PowerPoint

thumbnail image

Figure 2. ±45° bi-axial fabric.

Download figure to PowerPoint

thumbnail image

Figure 3. 0°, ±45° tri-axial fabric.

Download figure to PowerPoint

Table 1. Test board specifications.
 Freeride test boardVersatile test boardFreestyle test board
  1. a

    UHMWPE, ultra-high molecular weight polyethylene.

Length159 cm157 cm154 cm
Core MaterialAluminium honeycombWoodWood
Layer Composition • Upper single bi-axial fiberglass layer 
 • Upper and lower single tri-axial fiberglass layers• Lower single tri-axial fiberglass layer• Upper and lower single bi-axial fiberglass layers
 • Epoxy resin• Carbon reinforcing strips• Epoxy resin
  • Epoxy resin 
Base MaterialSintered UHMWPESintered UHMWPEExtruded UHMWPE
TopsheetABSABSABS

All three snowboards were subjected to static bending and torsional deflection tests at three different temperatures, 22°C, 4°C and −17°C. Measurements of the self-weighted camber were also taken at each temperature. Table 2 summarizes the testing conditions for each set of experiments.

Table 2. Testing conditions.
Temperature22°C4°C−17°C
Variance±2°C±0.5°C±2°C
LocationLaboratoryIndustrial fridgeIndustrial freezer

2.1 Bending Stiffness

The bending stiffness of the test boards was calculated using the following standard equation:

  • equation image(1)

Where EI is the bending stiffness (N.m2), M is the applied moment (N.m) and f′′ is the curvature of the snowboard (m−1). The apparatus designed for the tests is shown in Figures 4–6. The test rig displayed in Figure 4 consists of a 1500-mm long C-channel base, two adjustable supports with 20-mm diameter rollers (capable of supporting the entire width of the snowboards from tip to tail), and a load (F) application device consisting of two 20-mm diameter rollers supporting two 11-kg masses via hooks. This particular setup allowed the calculation of the bending stiffness in the body section of the test boards. To determine the bending stiffness at the heel and shovel of the snowboards, a different setup was required, as shown in Figure 5. For these tests, the forebody or aftbody of the board was clamped using 40-mm wide metal plates, and the board was deflected using 22 kg of total mass, 100 mm from tip to tail.

thumbnail image

Figure 4. Bending tests rig. F, load (© 2009 International Sports Engineering Association. Reproduced with kind permission).

Download figure to PowerPoint

thumbnail image

Figure 5. Alternate setup, F, load (© 2009 International Sports Engineering Association. Reproduced with kind permission).

Download figure to PowerPoint

thumbnail image

Figure 6. Curvature measurement device (© 2009 International Sports Engineering Association. Reproduced with kind permission).

Download figure to PowerPoint

Figure 6 shows the apparatus used to calculate the curvature of the snowboard, consisting of a 20-mm comparator positioned centrally in a 200-mm C-section. The device allowed for the accurate measurement of the localized, relative deflection (δ) at 50-mm intervals along the chord, and thus, calculation of the curvature using the following simple geometry (shown in Figure 7):

Using Pythagoras's theorem:

  • equation image(2)

When R>>x,

  • equation image(3)
thumbnail image

Figure 7. Curvature geometry (© 2009 International Sports Engineering Association. Reproduced with kind permission).

Download figure to PowerPoint

Thus, the curvature (1/R) could easily be determined. Due to the assumptions and simplifications inherent in the calculation of the curvature, the maximum error in the final bending stiffness values was calculated at approximately 5%. For a full comparison and analysis of the variation in bending stiffness distributions between the three major riding styles, refer to Subic et al. 2.

2.2 Torsional Stiffness

The torsional stiffness profiles were obtained using the following standard equation:

  • equation image(4)

Where GJ represents the torsional stiffness (N.m2), T is the applied torque (N.m), ϕ is the angular deformation (rad) and d is the length of the area under consideration (m). Given that the board materials were non-homogenous, the measurements were made upon four portions of the board approximately 200 mm long. Although it should ideally have been as small as possible, this length was chosen due to angle measurement accuracy considerations, and thus was considered appropriate. Figure 8 displays the approximate segmenting of the board for the torsional tests. Using the same rig as per the forebody and aftbody bending tests to clamp the board, the portion under consideration was twisted using a dual system, comprising of a hanging mass on one side of the snowboard, and a mass pulling the board upward via a pulley and flagstaff on the opposing side. This setup is shown in Figure 9. Note that the masses applied to each test board varied between 23 and 11 kg, to ensure adequate angular displacement without straying into the plastic deformation zone.

thumbnail image

Figure 8. Board measurement sections, d, length of area under consideration (m) (© 2009 International Sports Engineering Association. Reproduced with kind permission).

Download figure to PowerPoint

thumbnail image

Figure 9. Torsion tests rig, F, load (© 2009 International Sports Engineering Association. Reproduced with kind permission).

Download figure to PowerPoint

The board was clamped in four separate configurations for the tests. Firstly, the basic forebody/aftbody tests were conducted, whereby the board was clamped along the center line, with the rollers positioned 170 mm from tip to tail. Secondly, in order to simulate the twist applied to the snowboard body section by the rider, the board was clamped at the forward binding location, with the rollers positioned on the aft binding inserts. This test was repeated with the opposing setup, with both tests utilizing a test section of the stance width plus 100 mm.

To calculate the resulting angular deformation along each test section, again a comparator (on a guided rail) was utilized to measure the vertical displacement at 50 mm intervals along the board edge, which were then converted into angles using the board width distribution and the following simple geometry (shown in Figure 10):

Angular deflection:

  • equation image(5)
thumbnail image

Figure 10. Angular deflection measurement (© 2009 International Sports Engineering Association. Reproduced with kind permission).

Download figure to PowerPoint

Where a is the distance from the center line of the board, and b is the vertical displacement. For an in depth comparison of the torsional stiffness profiles across the major riding styles, refer to Subic et al. 2. Note that unlike the bending profiles, which were calculated from tip to tail, the difficulty in undertaking the torsional measurements on the curved heel and shovel sections meant that these areas of the board were neglected. However, considering that torsional stress on the board is imparted almost solely by the riders' feet, the torsional stiffness in the center section of the snowboard is of paramount importance. Compared to the bending profiles, the torsional characteristics possessed a comparable maximum margin of error, estimated at approximately 8%, primarily due to the 200-mm segmenting length and angular measurement inaccuracy.

2.3 Camber Properties

The camber of each test board was determined using a simple setup consisting of a comparator on a stand. It was calculated along the center line of each snowboard by comparing readings when the board was pressed flat, and second, when resting under only its own weight. Several measurements were taken, and the results were averaged. The maximum error in the measurements was about 4%.

3. RESULTS

  1. Top of page
  2. Abstract
  3. 1. INTRODUCTION
  4. 2. EXPERIMENTAL INVESTIGATION
  5. 3. RESULTS
  6. 4. DISCUSSION
  7. 5. CONCLUSION
  8. REFERENCES

3.1 Bending and Torsional Stiffness

The results of the static bending and torsional deflection tests for each snowboard are shown in Figures 11–13 and 14–16 respectively. The main trend identified from all bending and torsional stiffness characteristic graphs was an increase in overall stiffness with a decrease in temperature. Most of the stiffness gain occurred when the temperature was reduced from 22°C to 4°C; there was negligible stiffening between 4°C and −17°C for all three test boards. Despite the heterogeneous layered construction of the snowboards, the overall shape of each stiffness profile was not affected by temperature variation. It is noted that the calculated margin of error in the bending and torsional stiffness data was about 5% and 8% respectively.

thumbnail image

Figure 11. Freeride test board bending stiffness comparison.

Download figure to PowerPoint

thumbnail image

Figure 12. Versatile test board bending stiffness comparison.

Download figure to PowerPoint

thumbnail image

Figure 13. Freestyle test board bending stiffness comparison.

Download figure to PowerPoint

thumbnail image

Figure 14. Freeride test board torsional stiffness comparison.

Download figure to PowerPoint

thumbnail image

Figure 15. Versatile test board torsional stiffness comparison.

Download figure to PowerPoint

thumbnail image

Figure 16. Freestyle test board torsional stiffness comparison.

Download figure to PowerPoint

Each test snowboard exhibited different variations in stiffness. The freeride test board had the smallest variation over the total temperature range in both bending and torsion, with a total increase in integrated average stiffness of 11.5% and 6.5%, respectively. However, only 1.6% and 0.6% of these respective gains occurred when the temperature fell from 4°C to −17°C. The freestyle test board displayed average stiffness gains in bending and torsion of 14.7% and 17.1%, respectively, yet again only minor changes between 4°C and −17°C (0.5% and 0.6%, respectively). The versatile board provided the most interesting results, with a total observed average bending stiffness increase of 11.9% (1.4% between 4°C and −17°C), but a total increase in average torsional stiffness of 22.4% (1.9% between 4°C and −17°C).

3.2 Camber Properties

The camber measurements presented in Table 3 show exactly the same trends as the bending and torsional stiffness data, whereby camber levels were significantly greater at the lower temperatures for all three snowboards. Furthermore, the results were essentially constant between 4°C to −17°C, with a maximum difference of 0.3 mm between the three test boards, which is less than the calculated maximum margin of error of 4% (or 0.31 mm). However, the percentage increases in camber levels for the test boards with decreasing temperature were considerably larger than the corresponding increases in average bending and torsional stiffness. This was the case particularly for the highly-flexible versatile test board, which exhibited a 75% increase in maximum camber height, although only 2.3% between 4°C and −17°C, well within the data error range. The highly-stiff freeride board experienced a 17.3% increase in camber over the total temperature range (2.5% between 4°C and −17°C), while the freestyle test board exhibited a 45.6% change (3.8% between 4°C and −17°C).

Table 3. Camber comparison (in mm).
 Freeride test boardVersatile test boardFreestyle test board
22°C8.14.47.9
4°C9.37.611.2
−17°C9.57.711.5

4. DISCUSSION

  1. Top of page
  2. Abstract
  3. 1. INTRODUCTION
  4. 2. EXPERIMENTAL INVESTIGATION
  5. 3. RESULTS
  6. 4. DISCUSSION
  7. 5. CONCLUSION
  8. REFERENCES

4.1 Bending and Torsional Stiffness

As the overall geometry of each snowboard remained constant during the temperature dependent tests (aside from some thermal contraction/expansion), the different stiffness gains of the three snowboards can be attributed to their different composite sandwich construction. The stiffest board – the freeride – constructed with an aluminium honeycomb core and two tri-axial layers of fibreglass, exhibited the most constant stiffness response over the temperature range. Conversely, aside from the very large increase in torsional stiffness displayed by the versatile test board, the freestyle test board made with a wooden core and bi-axial fibreglass layers showed the highest temperature dependence.

Overall, the versatile and freestyle test snowboards constructed with a wooden core and bi-axial fibreglass skins showed larger stiffness increases than the freeride board made using aluminium honeycomb and tri-axial fibreglass skins. The differences in the stiffness-temperature responses of the boards were partly due to differences in the temperature dependent elastic properties of the fibreglass skins and core materials. The stiffness of the bi-axial fibreglass skins has a greater dependency on the elastic properties of the epoxy matrix than the tri-axial fibreglass skins. This is because the bi-axial skins only have glass fibres in two reinforcement directions (normally +45°/−45° though other angles are possible), whereas tri-axial skins have three reinforcement directions (0°/+45°/−45°). Thus depending on the fibre angles utilised in the fabric, either the bending stiffness (governed by longitudinal or 0° stiffness) or torsional stiffness (governed by +45°/−45° stiffness) of bi-axial fibreglass skins are influenced more strongly by the matrix properties than the fibre properties. Conversely, the stiffness of the tri-axial fibreglass skins is less dependent on the matrix properties. The stiffness of glass fibres is insensitive to changes in temperature over the range studied (−17°C to 22°C), whereas the elastic modulus of the epoxy matrix increases with temperature. This stiffness gain is a result of decreased mobility of the polymer network structure, which slows the movement of the chains under an external applied load resulting in higher rigidity. Therefore, the overall stiffness of the bi-axial fibreglass skins shows a larger increase than the tri-axial skins when the temperature is reduced.

Another factor influencing the bending and torsional stiffness properties of the snowboards was the temperature dependent elastic modulus of the core materials. The stiffness of the polymer encased wood (restricting moisture changes) increases as the temperature is reduced, whereas the elastic modulus of the aluminium honeycomb remains constant. The elastic properties of wood are controlled primarily by the stiffness of the cell walls, which are composed mostly of hemi-cellulose and lignin fibrils. The mobility of the hemi-cellulose and lignin molecules decreases with temperature, which results in higher stiffness to the wood. It is possible that freezing of water within the cell walls into microcrystallites may also decrease the molecular mobility of the hemi-cellulose and lignin. These stiffening mechanisms were believed to be partly responsible for the greater increase in the bending and torsional stiffness of the snowboards containing a wooden core with decreasing temperature.

The elastic properties of the UHMWPE base layer and ABS topsheet present on all three test boards are also temperature dependent. Again, this is a result of reduced molecular mobility, whereby the molecules do not move as easily under an externally applied stress when the temperature drops. The outermost layers of each snowboard, despite their relatively small thickness, have a significant influence on the bulk stiffness-temperature properties due to their elastic modulus increasing significantly with decreasing temperature and their distance from the neutral bending axis. Decreasing the temperature from 22°C to −17°C will increase the elastic modulus of the UHMWPE and ABS layers by about 70% and 200–300%, respectively (the exact response of ABS in the tested temperature range is unknown) 8, 9. Implementing these stiffness gains in an elastic stress-strain analysis of a laminated snowboard, the resulting increase in bulk bending and torsional stiffness was approximately 4.5% and 7.5% respectively. Therefore, the stiffness gains of the snowboards with decreasing temperature was due to increases in the elastic properties of the fibreglass skins, wood core, UHMWPE base layer and ABS topsheet.

4.2 Camber Properties

Despite the large percentage changes in camber exhibited by the test snowboards, examining the actual increases in total camber (in millimetres), trends similar to those noted for the bending and torsional stiffness data were apparent. Again the stiffest freeride board showed the most constant response over the temperature range (1.4 mm camber gain), whilst the freeride and versatile test boards both exhibited a camber increase of about 3.5 mm. It was postulated that the camber changes for all three test boards were caused by the differences in thermal expansion coefficients of the constituent layers (Table 4). Upon cooling, the UHMWPE base layer would have contracted to a far greater extent than the other layers in the composite sandwich, thus causing the snowboard to bend upwards, increasing the camber.

Table 4. Thermal expansion coefficients 14
 α (10−6/°C)
  1. a

    UHMWPE, ultra-high molecular weight polyethylene.

Wood (spruce) (parallel to grain)3.4–6.1
Aluminium honeycomb21.5–23.6
Fiberglass (parallel to fibers)5.0
Epoxy resin81–117
UHMWPE234–360
ABS65–95

The different camber changes between the test boards could also be rationalised in a similar manner, where the wooden core snowboards possessed significantly larger contraction rate differentials than the aluminium honeycomb core snowboard, thus confirming the far larger camber gains shown for the freestyle and versatile test boards. The small gains in the 4°C to −17°C temperature range were more difficult to justify, however studies have shown that epoxy resin and UHMWPE exhibit significant reductions in their thermal expansion coefficient with temperature 10–12, as opposed to wood and aluminium which have essentially constant coefficients 11, 13. Thus the thermal expansion differentials between the layers of each test snowboard would have reduced significantly with temperature, providing an explanation for the camber results.

5. CONCLUSION

  1. Top of page
  2. Abstract
  3. 1. INTRODUCTION
  4. 2. EXPERIMENTAL INVESTIGATION
  5. 3. RESULTS
  6. 4. DISCUSSION
  7. 5. CONCLUSION
  8. REFERENCES

The selected snowboards spanning the major riding styles were tested under three different temperature conditions. The bending and torsional stiffness and the camber increased with a reduction in temperature for all three snowboards. However between 4°C and −17°C, these key design parameters remained essentially constant.

The changes in stiffness were different for each type of composite structure. The elastic properties of the fibreglass skins that are matrix dominated will increase more than skins with fibre dominated properties. The use of wood for the core instead of aluminium honeycomb also increases the stiffness with falling temperature. Finally, the elastic modulus of the polymeric topsheet and base layer present on all snowboards causes an increase in bending and torsional stiffness as the temperature is reduced. Conversely, camber change appears to be driven by thermal expansion differentials within the composite structure.

Given the almost constant response of the test snowboards between 4°C and −17°C, the on-snow performance of all three test boards would not be greatly affected by the usual temperature fluctuations present during snowboarding. Instead, the stiffening effect should be considered when undertaking various laboratory tests at room temperature, such as during vibrational analysis where calculated natural frequencies may be considerably different at on-snow temperatures. Any results would have to be scaled to incorporate the temperature effects, particularly when boards with different composite structures are being compared as even a relative comparison may be inaccurate.

Overall, this study has demonstrated the sensitivity of key snowboard design parameters such as stiffness and camber to temperature variations. Consideration of this particular behaviour must be incorporated into any analysis conducted at testing temperatures higher than on-snow temperatures.

  • 1

    Maximum height of the running surface of the snowboard measured unweighted on a plane surface.

REFERENCES

  1. Top of page
  2. Abstract
  3. 1. INTRODUCTION
  4. 2. EXPERIMENTAL INVESTIGATION
  5. 3. RESULTS
  6. 4. DISCUSSION
  7. 5. CONCLUSION
  8. REFERENCES
  • 1
    Subic A, Clifton P, Beneyto-Ferre J. Identification of innovation opportunities for snowboard design through benchmarking. Sports Technology 2008; 1(1): 6575.
  • 2
    Subic A, Clifton P, Beneyto-Ferre J, LeFlohic A, Sato Y, Pichon V. Investigation of snowboard stiffness and camber characteristics for different riding styles. Sports Engineering 2009; 11(2): 93101.
  • 3
    Kumar M, Chawla N, Priyadarsini A, Mishra I, Ray B. Assessment of microstructural integrity of glass/epoxy composites at liquid nitrogen temperatures. Journal of Reinforced Plastics and Composites 2007; 26(11): 10831089.
  • 4
    Soni S, Gibson R, Ayorinde E. The influence of subzero temperatures on fatigue behavior of composite sandwich structures. Composites Science and Technology 2009; 69(6): 829838.
  • 5
    Walsh R, McColskey K, Reed R. Low temperature properties of a unidirectionally reinforced epoxy fibreglass composite. Cryogenics 1995; 35(11): 723725.
  • 6
    Borsellino C, Calabrese L, Passari R, Valenza A. Study of Snowboard Sandwich Structures. In ThomsonOT, BozhevolnayaE, LyckegaardA (Eds.) Sandwich Structures 7: Advancing with Sandwich Structures and Materials. Aalborg, 29–31 August. Springer, Holland. 967976.
  • 7
    Grewal D, Rossetter E, Lund C, Ewers B. Experimental Measurement of Selected Snowboard Mechanical Properties. In EstivaletM, BrissonP (Eds.) The Engineering of Sport 7: Volume 2. Biarritz, 2–6 June. Springer, Paris. 279287.
  • 8
    Reding FP. The stiffness modulus of polyethylene as a function of temperature and structure. Journal of Polymer Science 1958; 32: 487502.
  • 9
    Scheirs J. Compositional and Failure Analysis of Polymers: A Practical Approach. John Wiley & Sons Ltd: Brisbane, 2000; 335.
  • 10
    Kanagaraj S, Pattanayak S. Thermal Expansion of Glass Fabric-Epoxy Composites at Cryogenic Temperatures. In Balachandran U, Adams M (eds.) Advances in Cryogenic Engineering: Transactions of the International Cryogenic Materials Conference, Volume 50. Anchorage, Alaska, 22–26 September 2003; 201208.
  • 11
    Pizzo B, Rizzo G, Lavisci P, Megna B, Berti S. Comparison of thermal expansion of wood and epoxy adhesives. Holz als Roh- und Werkstoff 2002; 60: 285290.
  • 12
    Jayanna H, Subramanyam S. Thermal expansion of irradiated polyethylene. Journal of Polymer Science, Part B: Polymer Physics 1993; 31: 10951098.
  • 13
    Wilson A. The thermal expansion of aluminium from 0° to 650°C. Proceedings of the Physical Society 1941; 53: 235244.
  • 14
    ASM International. ASM Handbooks Online. Volumes 1, 2 and 21. http://products.asminternational.org/hbk/index.jsp [1 September, 2008].