ENGINEERING PROPERTIES OF LAMINATES 



5-15 



a. Impacter at Top of 20 Ft. Long Seamless b. Panel Under Test on Supporting Frame 

 Steel Tube 



Fig. 5-4. Impact Test Equipment (Courtesy Budi Company) 



laminates tested was made on the basis of panel thickness and weight versus impact strength 

 values for the critical condition only, and are given in Figs. 5-5 and 5-6. The order of 

 relative impact resistance for these laminates was found to be: 



M2 and M5 - Woven roving and woven roving faced on each side with cloth. 



M3 - Cloth 



Ml and M5 - Mat and mat faced on each side with cloth. 



The addition of the cloth facings to the woven roving and mat laminates has little effect on 

 the impact strength. 



Figs. 5-5 and 5-6 can only give a relative indication of the effect of impact loading. No 

 test data is available which gives information on combined stresses due to impact plus other 

 loadings. Until such time as more data is available the designer will have to rely on exper- 

 ience and judgment for determining laminate configurations where these combined loads 

 may occur. 



