Skip to main content
Article thumbnail
Location of Repository

Speed and Temperature Effects in the Energy Absorption of Axially Crushed Composite Tubes

By P V Quentin Fontana

Abstract

The original thesis was written in 1989/90 on a Macintosh Plus with a processor at 8 Mhz and 2.5 Mb of RAM; it was written using Micro$oft Word Version 4 for the Macintosh and all of the figures, with the exception of the photographs, were included. Significant changes in computer technology have occurred in the years between the writing and the generation of this electronic copy in 2008, there have been some problems with backward compatibility of the software used, in particular with respect to the graphics handling capability, so there have been some significant problems with the use of old file formats; consequently not all of the figures are as clear as they were when the original was written.Tubes of glass reinforced thermosetting resins have been tested in axial compression between steel platens with one end chamfered to prevent critically high loads causing catastrophic centre failure. By testing in such a manner these tubes crush in a progressive and controlled manner, and are capable of exhibiting high levels of energy absorption, particularly when related to the material mass involved. Polymers are known to display viscoelastic behaviour and polymer composites are similarly sensitive to test speed and temperature. Energy absorption in tube crushing has been shown to be speed and temperature sensitive and the purpose of this project has been to understand the variability of the energy absorption and the associated mechanisms. The main aim has been to show how the two variables interrelate. The materials used have been produced by hot rolling of pre-preg cloth or by resinjection into closed moulds. Reinforcement has consisted of woven glass cloth or random glass mat; matrix materials have been epoxy and polyester resins. Trends to higher values of specific energy absorption with increasing speed have been observed for epoxy matrix tubes, while polyester matrix tubes have shown less certain trends and give lower values of specific energy absorption at high speeds. All the tubes have shown a rapid drop in specific energy absorption with increasing temperature above normal room temperature, with changes in crush mode being very apparent. At temperatures in excess of about 100 degrees C the tubes have failed by centre buckling, the transition temperature from normal crushing to buckling being sensitive to the crush speed. The interrelation between speed and temperature effects has been examined. Three factors that prevent simple interrelation have been identified; these are inertial effects of crush debris, residual stresses in the hoop direction of the tube and frictional heating in the crush zone. Speed sensitivity of the energy absorption has been determined over a range of temperatures and various features of these responses related to the responses of the material properties. Frictional temperature rises have been modelled mathematically and the predictions have been shown to be reasonably consistent with experimental measurements. These temperature rises have been shown to be important in determining the speed sensitive behaviour of the energy absorption levels, particularly for polyester resin matrix tubes tested at high speeds

Publisher: Department of Materials Science and Metallurgy
Year: 1990
OAI identifier: oai:www.repository.cam.ac.uk:1810/205359
Provided by: Apollo

Suggested articles

Citations

  1. (1974). 2 An analysis of thermally activated deformation. ibid.;
  2. 2 The origin of thermal strains in polyester cross-ply laminates. doi
  3. (1985). 49 Code of Federal Regulations, Standard No. 208; Occupant Crash Protection. (U.S. Government Printing Office,
  4. (1987). A Method of Predicting the Energy Absorption Capability of Composite Subfloor Beams. doi
  5. (1983). A Tensile Testing Technique for FibreReinforced Composites at Impact Rates of doi
  6. (1981). An Introduction to Composite Materials: doi
  7. (1986). Applications of Polymer Matrix Composites. ibid.;
  8. (1989). Award for Reinforced Plastic Suspension System. ibid;
  9. (1983). Axial Crushing of Fibre Reinforced Composite Tubes. doi
  10. (1980). Chopped-Strand-Mats, Technical Information Sheet;
  11. (1988). Collapse Triggering of Polymer Composite Energy Absorbing Structures.
  12. Comparison of Bevel and Tulip Triggered Pultruded Tubes for Energy Absorption. doi
  13. (1988). Composite Laminates, Technical Information Sheet.
  14. (1981). Composite Leaf Springs in Heavy Truck Applications. COMPOSITE MATERIALS.
  15. (1976). Crack Propagation and Arrest in Epoxy Resins. ibid.; doi
  16. (1978). Crack Propagation in an Amine Cured Epoxied Resin. doi
  17. (1979). Crack Propagation in and Fractography of Epoxy Resins. doi
  18. (1985). CRAG Test Methods for the Measurement of the Engineering Properties of Fibre Reinforced Plastics.
  19. Crash Energy Management in Composite Automotive Structures.
  20. (1986). Crash-Impact Behaviour of Tubular Composite Structures,
  21. (1983). Deformation and Fracture Behaviour of a Rubber-toughened Epoxy: 1. Microstructure and fracture studies. ibid.; doi
  22. (1983). Deformation and Fracture Behaviour of a Rubber-toughened Epoxy: 2. Failure Criteria. POLYMER; doi
  23. (1974). Deformation Characteristics of Reinforced Epoxy Resin: Part 1 The mechanical properties. ibid.; doi
  24. (1985). Design Development Tests for Composite Crashworthy Helicopter Fuselage. SAMPE QUATERLY;
  25. (1974). Determination of the K, v Diagram of Epoxied Resins. ibid.;
  26. (1983). Dry Wear Studies on GlassFibre-Reinforced Epoxy Composites. doi
  27. (1986). Effect of Specimen Geometry on the Energy Absorption of Composite Materials. doi
  28. (1984). Effect of Speed on Progressive Crushing of EpoxyGlass cloth Tubes. Harding
  29. Effect of Strain Rate on Material Properties.
  30. (1984). Effect of Strain Rate on the Tensile Failure of Woven Polyester Resin Composites. doi
  31. (1989). Effect of the Introduction of Methoxy Branches on Low-Temperature Relaxations and Fracture Toughness of Epoxied Resins. doi
  32. Effect of Trigger Geometry on Crush Initiation.
  33. (1985). Effect of Trigger Geometry on Energy Absorption in Composite Tubes. Harrigan
  34. Effects of Moisture and temperature on the Tensile Strength of Composite Materials. doi
  35. (1988). Energy Absorbing Composite Structures. SCIENCE AND TECHNOLOGY REVIEW;
  36. (1987). Energy Absorption and Failure
  37. (1989). Energy Absorption Behaviour of Graphite Epoxy Composite Sine Webs. doi
  38. (1987). Energy Absorption in Composite Materials for Crashworthy Structures.
  39. (1979). Energy Absorption in Composite Structures.
  40. (1982). Energy Absorption in Composite Tubes.
  41. (1982). Energy Absorption of Composite Materials Under crash Conditions.
  42. (1983). Energy Absorption of Composite Materials. doi
  43. (1988). Energy Absorption of Polymer Matrix Composite Structures: Frictional Effects.
  44. (1967). Engineering Thermodynamics Work and Heat Transfer: Longman;
  45. Epoxy Resin 7065N75. doi
  46. (1985). Fibre-reinforced Plastic Composites for Energy Absorption Purposes.
  47. (1978). Fracture Energy of Epoxy Resins Above Tg. ibid.;
  48. Fracture of Thermosetting Resins. doi
  49. (1963). Friction of Polymers: Influence of Speed and Temperature. doi
  50. (1983). Generation of Thermal Strains in GRP. Part 1 Effect of water on the expansion behaviour of unidirectional glass fibre-reinforced laminates. doi
  51. (1987). Glass Fibre Composites in the Automotive Industry.
  52. (1989). High Performance Dyneema Fibres in Composites. doi
  53. idem: Part 2 Effect of Plastic Deformation Upon Crack Propagation. doi
  54. (1987). Impact Energy Absorption of Continuous Fibre Composite Tubes. doi
  55. (1985). Impact Response of Structural Composites.
  56. (1980). Low temperature Crack Propagation in an Epoxide Resin. ibid.; doi
  57. (1989). Materials in Railway Engineering. ibid.;
  58. Materials Science Department, Ford Motor Co.,
  59. (1981). Measurement of Specific Energy Absorbed Values. EAC 1047: University of Liverpool;
  60. (1988). Mechanism of Radiation-Induced Degradation in Mechanical Properties of Polymer Matrix Composites. doi
  61. (1989). Mechanisms for Rate Effects on Interlaminar Fracture Toughness of Carbon/Epoxy and Carbon/PEEK Composites. ibid.; doi
  62. (1986). Performance Characteristics of Composite Materials. METALS and MATERIALS;
  63. Preparation and Radiation-Resistance Evaluation of Glass Fibre Composites Having Various Epoxy Matrices. ibid: 503-505; doi
  64. (1982). pt 8. Industural Laminated Rods and Tubes Based on Thermosetting Resins: doi
  65. (1989). Rate and Temperature Effects on Crack Blunting Mechanisms in Pure and Modified Epoxies. ibid.; doi
  66. (1987). Rate Effects on Mode I Interlaminar Fracture Toughness in Composite Materials. doi
  67. (1987). Report on Crush Testing of Square Section Resinject Glass/Polyester Tubes.
  68. Scaling Effects in the Energy Absorption of Axially Crushed Composite Tubes.
  69. (1979). Sliding Wear of Polymeric Composites. doi
  70. (1989). Spin-Offs for Safer Cars.
  71. (1983). Summary of SMC Development:
  72. (1980). Synthesis Procedure and the Fracture Toughness of Highly Cross-linked Resins. doi
  73. (1988). Temperature Dependence of Fracture Toughness of Epoxy Resins Cured with Diamines. doi
  74. (1978). Testing of Fiber Composites at High Strain Rates.
  75. (1956). Textbook of Physical Chemistry: Macmillian;
  76. (1985). The Abrasive Wear of Short Fibre Composites. COMPOSITES; doi
  77. (1986). The Crush Behaviour of Glass Fibre Reinforced Plastic Sections.
  78. The Crush Performance of Tube Sections and Slotted Tubes:
  79. The Daily Mail c.1987.
  80. (1976). The Effect of Water on the Critical Stress Intensity Factor of Unsaturated Polyester Resins. doi
  81. (1987). The Energy-Absorbing Properties of a Novel Cellular Structure. doi
  82. (1976). The Fracture of Highly Crosslinked Resins. An Invited Review. doi
  83. (1973). The Fracture Toughness and Crack Propagation Properties of Polyester Resin Casts doi
  84. (1976). The Fracture Toughness and Fracture Morphology of Polyester Resins. ibid.; doi
  85. (1974). The Low-temperature Macro Deformation of an Epoxide doi
  86. (1980). The Mechanical Properties of Epoxy Resins: Part 1 Mechanisms of Plastic Deformation. ibid.; doi
  87. (1936). The Physical Properties of Surfaces, III-The Surface Temperature of Sliding Metals, The Temperature of Lubricated Surfaces. doi
  88. (1986). The Potential for Composites in Structural Automotive Design. ibid.;
  89. (1961). Theory of Elastic Stability, doi
  90. (1985). Thermophysical Properties of Composite Materials: a State-of-the-Art Assessment.
  91. (1984). Thesis, doi
  92. (1990). Trigger Mechanisms in Energy Absorbing Glasscloth Epoxy Tubes. doi
  93. (1980). Unpublished work,

To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.