Effects of the Pre-strain on Mechanical Properties of the Solid-Phase Formed Thermoplastic Composite

고상성형된 열가소성 복합재료의 성형 변형률이 기계적 특성에 미치는 영향

Lee, Jung-Hui;Jo, Hyeon-Cheol;Lee, Gyeong-Yeop

  • Published : 2001.08.01


This study investigates the effects of the pre-strain level on mechanical properties of the solid-phase formed thermoplastic composite. A uniaxial solid-phase forming was performed at the temperature of 125$\^{C}$ and at the constant cross-head speed of 3mm/sec. The composite sheet was formed to various pre-strain levels of 10%, 20%, and 30%. Tension, flexural, and impact tests were carried out to characterize the material properties of a solid-phase formed part. Tensile and flexural strengths decreased with increasing the pre-strain level, while impact strength increased. Various microstructures of the formed part explained the above material behavior.


Solid-Phase Forming;Thermoplastic Composite;Pre-Strain;Material Properties;Rule of Mixture


  1. Lee, J. H. and Vogel, J. H., 1996, 'An Investigation of Necking Instability in Fiber Reinforced Polypropylene,' Journal of Engineering Materials and Technology, Vol. 118, pp. 80-87
  2. Matthews, F. L. and Rawlings, R. D., 1994, Composite Materials: Engineering and Science, Chapman & Hall, pp. 251-268
  3. 이대길, 1993, 복합재료 역학 및 가공론, 성안당, pp. 187-192
  4. Mallick, P. K. and Newman, S., 1990, Composite Materials Technology, Hanser Publisher, pp. 67-320
  5. Lee, J. H. and Vogel, J. H., 1995, 'Biaxuial Stretch Forming of Thermoplastic Composite Sheets,' 27th International SAMPE Technical Conference, Vol. 27, pp. 750-759
  6. Ericson, M. and Berglund, L., 1992, 'Deformation and Fracture of Glass Mat Reinforced Polypropylene,' Composite Science and Technology, Vol. 43, pp. 269-281
  7. Bigg, D. M., Hiscock, D. F., Preston, J. R., and Bradbury, E. J., 1988, 'Thermoplastic Matrix Sheet Composites,' Polymer Composites, Vol. 9, pp. 222-228
  8. Lee, J. H. and Vogel, J. H., 1995, 'An Investigation of the Formability of Long Fiber Thermoplastic Composite Sheets,' Journal of Engineering Materials and Technology, Vol. 117, pp. 127-132
  9. Crosby, J. M., 1988, 'Recent Advanced in Thermo-Plastic Composites,' Advanced Materials and Processes Inc. Metal Progress, pp. 56-59
  10. 이우일, 1987, '섬유강화 복합재료와 자동차산업에의 응용,' 자동차공학회지, Vol. 9, No. 6, pp. 8-14
  11. 이동기, 김정락, 김상필, 이우일, 김이곤, 1993, 'Thermoforming용 장섬유강화 복합재료의 성형공정에 관한 연구,' 대한기계학회논문집, 제 7권, 제 5호, pp. 1106-1114
  12. Bigg, D. M. and Preston, J. R., 1986, 'Stamping of Thermoplastic Matrix composite,' Polymer Composites, Vol. 10, pp. 261-268