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Abstract

The nature of impact testing has changed radically in recent years. Instrumentation and in-line data processing provide a force-deformation record of the impact event and other information; flash photography of the specimen at some predetermined instant during the impact enables correlations to be established between features on the impact response curve and stages in the development of damage; low energy impacts that damage, but do not destroy, the specimen enable the course of damage development to be determined. The three principal test configurations, tensile, flexed beam and flexed plate, are all satisfactory within limits; each has its deficiencies and each has its particular virtues. Whichever method is used, the data generated relate to the specimen rather than to the material from which it is made. The impact resistance of the material has to be inferred, with due allowance being made for the influence that the molecular state of the sample has on experimental results. The relationships between flow geometry features and impact resistance have not yet been quantified adequately but the required experimentation has been identified.

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References

Reed

P.E.

, Nurse

P.J.

and Andrews

E.H.

, ‘High Strain Rate Testing of Plastics. Part 1. Shock Tube Technique’, J. Mat. Sci., 9, 1977, 1974

Younan

, Hodgkinson

J.M.

and Williams

J.G.

, ‘Instrumented Falling Weight Impact Testing of PMMA’, P. R.P.A., 8, 4, 1987, 227

Johnson

A.E.

, Unpublished Information, Glass Fibres & Technology Group, Pilkington Bros. PLC

Johnson

A.E.

, Moore

D.R.

, Prediger

R.S.

, Reed

P.E.

and Turner

, ‘The Falling Weight Impact Test Applied to Some Glass-fibre Reinforced Nylons. Part 1 Appraisal of the Method’. J. Mat. Sci. 21, 1986, 3153

Kessler

S.L.

, Adams

G.C.

, Driscol

S.B.

and Ireland

D.R.

(Eds.), ‘Instrumented Impact Testing of Plastics and Composite Materials’, ASTM STP 936

Casiraghi

, Castiglioni

and Ajroldi

, ‘New Developments in the Assessment of Impact Resistance Evaluation by Falling Weight Method’, P. R.P.A. 2, 4, 1982 353

Dorey

and Bishop

S.M.

, ‘Impact Performance of Carbon Fibre/PEEK Composites', Paper No. 18, International Conference on Impact Testing and Performance of Polymeric Materials, 2—3 September 1985, University of Surrey, Guildford, September 1985

Jones

D.P.

, Leach

D.C.

and Moore

D.R.

, The Application of Instrumented Falling Weight Impact Techniques to the Study oi Toughness in Thermoplastics'. P.R.P.A. 6, 2, 67, 1986

Vincent

, ‘Impact Tests and Service Performance of Thermoplastics', Plastics Institute Monograph, 1971

10.

Cole

E.A.

, ‘The Relevance of Impact Tests to the Quality of Injection Mouldings', Plastics & polymers, 43, 1975, 181

11.

Hooley

C.J.

and Turner

, ‘Mechanical Testing of Plastics', Automotive Engineer, June/July 1978 p. 48

12.

Cogswell

F.N.

, Cole

E.A.

and Turner

, ‘Rheology and Mechanical Properties: Study

of the Influence of Processing History on the Impact Resistance of Thermoplastics’. J. of Elastomers & Plastics, 11,3, 1979, 171

13.

Turner

and Reed

P.E.

, ‘Flexed Plate Impact Testing — Results for a Polypropylene and Some Experiments with Notched Specimens'. Kunststoffe German Plastics 76, 7, 1986, 30

14.

Martinez

, Reed

P.E.

and Turner

, ‘Flexed Plate Impact Testing of Poly(Ether Sulphone). part 2. Notched Specimens’, J. Mat. Sci. 21, 1986, 3801

15.

Hong

, Parsons

, Reed

P.E.

and Turner

, ‘Theoretical Studies of the Impact Penetration of Polymer Discs’. To be published

16.

Plati

and Williams

J.G.

, ‘The Determination of the Fracture Parameters for Polymers in Impact'. Poly. Eng. Sci., 15, 6, 1976, 470

17.

Moore

D.R.

, Stephenson

R.C.

and Whale

, ‘Some Factors Affecting Toughness in UPVCPipe Materials'. P.R.P.A. 3,1, 1983, 53

18.

Turner

— Collator, ‘ Study

of Impact Strength Testing and Its Relevance to Real Mouldings’. IUPAC Working Party Report. Pure & Applied Chemistry, 52, 1980, 2739

19.

Crawford

R.J.

and McGonagle

, ‘The Effect of Injection Moulding Conditions on the Impact Strength of Thermoplastics’, P. R.P.A. 3, 1, 1983, 43

20.

Turner

, ‘Modern Design Data for Short-Fiber Thermoplastic Composites'. J. Poly. Sci: Polymer Symposium 72, 1985, 319

Impact Testing and Evaluation

Abstract

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References