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see also: [[Impact Loading High-Speed Testing|Impact loading high-speed testing]]

Determination of the strength of PP/GF composites in high-speed tensile testing 
__FORCETOC__

==Introduction==

In many applications, for example in automotive engineering, aerospace technology and the sports sector, high [[Strain Rate Applications|strain rates]] of up to 500 s-1 can occur in the [[Material & Werkstoff|material]] or [[Plastic Component|component]] [1–3]. The automotive industry, in particular, places high demands on the safety and reliability of its vehicles and invests significant resources in experimental and computational work to meet these requirements. In Europe, crash tests are conducted in accordance with the European New Car Assessment Programme (EuroNCAP). Through a series of tests, this programme assesses the performance of vehicles in frontal and side impacts, pedestrian protection and other relevant areas.

'''Figure 1''' shows a schematic representation of a frontal crash, as well as the temporal sequences during the crash with the maximum strain rates occurring during the event. Determining the mechanical properties under these relevant operating conditions is important and necessary in order, on the one hand, to make a scientifically well-founded choice of materials and, on the other hand, to be able to carry out profound material development (see also: [[Materials Science|material science]]). Similarly, the provision of material property data for FEM simulations is becoming increasingly important [3–9].

[[File:HighSpeedTensileTest-Fig1.jpg|600px]]
{|
|- valign="top"
|width="50px"|'''Fig. 1''':
|width="600px" |Schematic representation of a frontal collision, showing the characteristic maximum strain rates that occur and a chronological description of the crash process, based on [6, 10, 11]
|}

The influence of [[Strain Rate Basics|strain rate]] on [[Strength|strength]] is described extensively in the literature, particularly for metals, including at higher temperatures [12–21]. The influence of measurement techniques on the interpretability of ''σ''–''ε'' diagrams, and thus on the validity of the results, is also discussed. The entire spectrum of strain rates is taken into account, ranging from [[Quasi-static Test Methods|quasi-static]] to [[Impact Loading High-Speed Testing|highly dynamic]] processes.

[[Servo-hydraulic Testing Machine|Servo-hydraulic testing machines]] can cover the strain rate range of < 300 s-1, which is important for technical applications, under various [[Stress|loading conditions]]; this is why high-speed tensile testing is becoming increasingly significant, a trend reflected in the growing international activity towards standardisation [22–27].

==Experimental section==

[[Short-fibre Reinforced Plastics|Short-fibre-reinforced]] polypropylene composites ([[Plastics – Symbols and Abbreviated Terms|abbreviation]]: PP/GF) were investigated. Due to the non-polar nature of polypropylene, maleic anhydride (MA) was used as a coupling agent to optimise the bonding of the fibres to the matrix. Kardelky [28] and Schröder [29] demonstrated that, compared to other nucleating agents for PP/GF composites, Echtblau achieves the best mechanical properties at a content of 0.01% by mass. For this reason, Echtblau was used as the nucleating agent. For the glass fibre contents listed in '''Table 1''', [[Multipurpose Test Specimen|multipurpose test specimens]] of type 1A, with a gauge length of 115 mm, were used, analogous to the quasi-static [[Tensile Test|tensile test]].

{| border="1px" style="border-collapse:collapse"
|+ '''Table 1''': Materials tested in high-speed tensile testing
!! style="width:150px; background:#DCDCDC" | matrix
!! style="width:150px; background:#DCDCDC" | mass fraction <math>\Psi</math> (-)
!! style="width:150px; background:#DCDCDC" | volume fraction ''φ''v (-)
|-
|rowspan=4 style="text-align:center"| PP
|style="text-align:center" | 0
|style="text-align:center" | 0
|-
|style="text-align:center" | 0.2
|style="text-align:center" | 0.083
|-
|style="text-align:center" | 0.3
|style="text-align:center" | 0.135
|-
|style="text-align:center" | 0.4
|style="text-align:center" | 0.193
|}

The high-speed train tests were conducted in accordance with Parts 1 and 2 of ISO 527 [30, 31], both in terms of test conditions and the choice of test specimen shape.

{| border="1px" style="border-collapse:collapse"
|+ '''Table 2''': [[Crosshead Speed|Crosshead speeds]] and nominal [[Strain Rate Basics|strain rates]] of all materials examined
!! style="width:270px; background:#DCDCDC" | Crosshead speed under load vT (m/s)
!! style="width:200px; background:#DCDCDC" | Nominal strain rate ε̇ (s-1)
|-
|style="text-align:center" | 0.00083
|style="text-align:center" | 0.007
|-
|style="text-align:center" | 0.01
|style="text-align:center" | 0.087
|-
|style="text-align:center" | 0.1
|style="text-align:center" | 0.87
|-
|style="text-align:center" | 1
|style="text-align:center" | 8.7
|-
|style="text-align:center" | 2
|style="text-align:center" | 17.4
|-
|style="text-align:center" | 5
|style="text-align:center" | 43.5
|-
|style="text-align:center" | 10
|style="text-align:center" | 87
|-
|style="text-align:center" | 20
|style="text-align:center" | 174
|}

The tests were carried out on a [[Servo-hydraulic Testing Machine|servo-hydraulic testing machine]] VHS 25/25-20 manufactured by INSTRON (High Wycombe, UK). This testing machine (see also: [[Impact Loading High-Speed Testing|impact loading high-speed testing]]) is capable of a maximum test speed of 20 m/s and a maximum load of 20 kN. The [[Test Speed|test speeds]] selected for the evaluation of the material properties and the nominal [[Strain Rate Basics|strain rates]] ''ε̇’'' resulting from the specimen dimensions and the gauge length are listed in '''Table 2'''. Taking into account the identical gauge length of 115 mm, the [[Strain Rate Applications|strain rate]] in the [[Quasi-static Test Methods|quasi-static]] [[Tensile Test|tensile test]] (50 mm/min) is 0.007 s-1.

==Example==

The basis for determining strength parameters in a [[Tensile Test|tensile test]] is the recording of load–extension diagrams (''F''–''l'' diagrams), followed by the calculation of stress (''σ'') and strain (''ε'') values. The ''σ''–''ε'' diagrams for PP materials are shown in '''Figure 2a–d'''.

{|
|[[File:Spannungs-Dehnungs-Diagramm-2a.jpg|300px]]
|[[File:Spannungs-Dehnungs-Diagramm-2b.jpg|300px]]
|-
|[[File:Spannungs-Dehnungs-Diagramm-2c.jpg|300px]]
|[[File:Spannungs-Dehnungs-Diagramm-2d.jpg|300px]]
|-
|}
{|
|- valign="top"
|width="50px"|'''Fig. 2''':
|width="600px" |[[Tensile Test#Tensile test, stress–strain diagram|Stress–strain diagrams]] for PP (a), PP/20 (b), PP/30 (c) and PP/40 (d) as a function of the strain rate
|}

The ''σ''–''ε'' curves shown in the figures, obtained at the lowest [[Strain Rate Applications|strain rate]] of 0.007 s-1, were determined under quasi-static loading conditions using a [[Material Testing Machine|universal testing machine]]. The graphical representation of the results reveals differences for the unreinforced materials as a function of the [[Strain Rate Basics|strain rate]]. For example, the formation of a [[Yield Stress|yield point]] is characteristic of PP, whereas for PB-1 the stress increases continuously until [[Fracture|fracture]].

As the [[Test Speed|test speed]] and thus the strain rate increase, the [[Strength|strength]] increases whilst the strain decreases. The addition of glass fibres increases the strength level, whilst the elongation at break decreases. The strength level for the PP material system is higher than that for the PB-1 material system for all strain rates and as a function of the [[Ashing Method|glass fibre content]]. The measurement of elongation using a strain gauge, which is standard in quasi-static [[Tensile Test|tensile testing]] (see: [[Tensile Test#Tensile test, path measurement technique|tensile test, path measurement technique]]), provides more accurate values than the determination based on the crosshead path. For this reason, there is no qualitative discussion of the minor differences in the elongation values obtained from the high-speed tensile test.

The ''σ''–''ε'' diagrams show that, at a strain rate of approximately 17.4 s-1 and above, the behaviour of the curves is predominantly characterised by the oscillations that occur as a result of the sudden loading. This applies equally to both material systems. At a strain rate of 174 s-1, only a half-wave of a fully reflected stress wave N (see: [[Strain Rate Basics|strain rate basics]]) can be observed in the reinforced materials ('''Figure 2b–d'''), which makes the analysis considerably more complicated.

A more detailed description of the strain rate-dependent strength behaviour of the materials using the G’SELL-JONAS model, as well as the [[Fracture Behaviour|fracture behaviour]] of the materials in high-speed tensile testing, can be found in the following publications [32, 33].

==See also==

* [[Impact Loading High-Speed Testing|Impact loading high-speed testing]]
* [[Strain Rate Basics|Strain rate basics]]
* [[Strain Rate Applications|Strain rate applications]]
* [[Velocity]]

==References==

{|
|-valign="top"
|[1]
|Bardenheier, R.: Dynamic Impact Testing – VHS High Rate Testing Systems. Instron Ltd., High Wycombe, UK (2005)
|-valign="top"
|[2]
|Thoma, K.: Measurement of Mechanical Parameters in the Range of High and Highest Strain Rates – Examples of Practical Application for a Wide Spectrum of Materials. Report 17/02. Fraunhofer-Institut für Kurzzeitdynamic – Ernst-Mach-Institut EMI Freiburg (2002)
|-valign="top"
|[3]
|Xiao, X.: Dynamic tensile testing of plastic materials. Polymer Testing 27 (2008) 164–178 DOI: https://doi.org/10.1016/j.polymertesting.2007.09.010
|-valign="top"
|[4]
|Dean, G., Read, B.: Modelling the behaviour of plastics for design under impact. Polymer Testing 20 (2001) 677–683 DOI: https://doi.org/10.1016/S0142-9418(01)00003-4
|-valign="top"
|[5]
|Bardenheier, R., Cordes, M.: Hochgeschwindigkeitsversuche und Crashsimulation – Technische Möglichkeiten. Tagung Werkstoffprüfung Deutscher Verband für Materialforschung und -prüfung e.V., Bad Nauheim (2000) (ISSN 0941-5300; see [[AMK-Library]] under M 34)
|-valign="top"
|[6]
|Werner, H., Gese, H.: Zur Bedeutung dehnratenabhängiger Werkstoffkennwerte in der Crashsimulation. In: Frenz, H., Wehrstedt, A. (Eds.): Kennwertermittlung für die Praxis – Proceedings Werkstoffprüfung (2002) 139–146, ISBN 3-527-30674-9; The manuscript was not available at the time of printing; see [[AMK-Library]] under M 10
|-valign="top"
|[7]
|Luke, M.: Dynamische Kennwertermittlung und Bauteil-Crashtests. Fraunhofer Institut für Werkstoffmechanik, Leistungsbereich Fahrzeugtechnik, Leichtbau (2003)
|-valign="top"
|[8]
|[https://de.wikipedia.org/wiki/Ernst_Schmachtenberg Schmachtenberg, E.]] (https://de.wikipedia.org/wiki/Ernst_Schmachtenberg), Brinkmann, M.: Crashsimulation. Kunststoffe 11 (2005) 135–138 [https://res.cloudinary.com/sternwald-systems/raw/upload/v1/hugoprd/ARTIKEL_ATTACH/0023FEFB_D40E0AEA3FAE/e6742ae23d84a4050ac230c7fbf2ea8dbd45b8cc/KU_2005_11_Materialdatenermittlung-Crashsimulation.pdf Download as pdf]
|-valign="top"
|[9]
|DuBois, P. A., Kolling, S., Koesters, M., Frank, T.: Material behaviour of polymers under impact loading. International Journal of Impact Engineering 32 (2006) 725–740 DOI: https://doi.org/10.1016/j.ijimpeng.2005.02.007
|-valign="top"
|[10]
|Frontal Impact Testing Protocol (March 2004): European New Car Assessment Programme (EuroNACP)
|-valign="top"
|[11]
|Buchele, C.: Sicherheitssysteme für Personenkraftwagen. Sicherheitsaspekte in technischen Systemen (SiS). Friedrich-Alexander-Universität Erlangen-Nürnberg (09.12.2004)
|-valign="top"
|[12]
|Thoma, K., Junginger, M.: Messung mechanischer Kennwerte im Bereich hoher und höchster Dehnraten – Beispiele aus der Praxis für ein weites Spektrum von Werkstoffen. In: Frenz, H., Wehrstedt, A. (Eds.): Kennwertermittlung für die Praxis – Proceedings Werkstoffprüfung (2002) 13–27, (ISBN 3-527-30674-9; see [[AMK-Library]] under M 10)
|-valign="top"
|[13]
|Häcker, R., Wossidlo, P.: Der Einfluss der Belastungsgeschwindigkeit im Zugversuch auf die Anforderungen an die Messtechnik und auf das Probenverhalten. In: Pohl, M. (Eds.): Konstruktion, Qualitätssicherung und Schadensanalyse – Proceedings Werkstoffprüfung (2004) 61–66, (ISBN 3-88355-337-9; see [[AMK-Library]] under M 12)
|-valign="top"
|[14]
|Hamouda, A. M. S., Hashmi, M. S. J.: Testing of composite materials at high rates of strain: Advances and challenges. Journal of Materials Processing Technology 77 (1998) 327–336 DOI: https://doi.org/10.1016/S0924-0136(97)00436-6
|-valign="top"
|[15]
|Bleck, W., Larour, P., Bäumer, A., Noack, J.: Einflüsse der Messtechnik auf die Ergebnisse von Hochgeschwindigkeitszugversuchen. In: [https://de.wikipedia.org/wiki/Michael_Pohl_(Metallurg) Pohl, M.] (Ed.): Konstruktion, Qualitätssicherung und Schadensanalyse – Proceedings Werkstoffprüfung (2004) 45–54, (ISBN 3-88355-337-9; see [[AMK-Library]] under M 12)
|-valign="top"
|[16]
|Guden, M., Hall, I. W.: High strain-rate compression testing of a short-fiber reinforced aluminum composite. Materials Science & Engineering, A: Structural Materials: Properties, Microstructure and Processing 232 (1997) 1–10 DOI: https://doi.org/10.1016/S0921-5093(96)10880-7
|-valign="top"
|[17]
|Häcker, R., Wossidlo, P.: Hochgeschwindigkeitszugversuche im Temperaturbereich von -100°C bis 300°C. 2. VHS-Anwendertreffen, Aachen, Germany, 15. September 2005.
|-valign="top"
|[18]
|Bleck, W., Larour, P.: Effect of Strain Rate and Temperature on the Mechanical Properties of LC and IF Steels. IF Steels 2003, Int. Forum for the Properties and Application of IF Steels, Tokio, Japan, 12–14 May 2003.
|-valign="top"
|[19]
|Bleck, W., Larour, P.: Measurement of the Mechanical Properties of Car Body Sheet Steel at High Strain Rates and Non-ambient Temperature. Conference Proceedings: Dymat 2003, 7th International Conference on Mechanical and Physical Behaviour of Material under Dynamic Loading, Porto, Portugal (2003) 489–493.
|-valign="top"
|[20]
|El-Magd, E., Abouridouane, M.: Characterization, modelling and simulation of deformation and fracture behaviour of the light-weight wrought alloys under high strain rate loading. International Journal of Impact Engineering 32 (2006) 741–758 DOI: https://doi.org/10.1016/j.ijimpeng.2005.03.008
|-valign="top"
|[21]
|Clausen, A. H., Borvik, T., Hopperstad, O. S., Benallal, A.: Flow and fracture characteristics of aluminium alloy AA5083-H116 as function of strain rate, temperature and triaxiality. Materials Science & Engineering, A: Structural Materials: Properties, Microstructure and Processing 364 (2004) 260–272 DOI: https://doi.org/10.1016/j.euromechsol.2005.10.007
|-valign="top"
|[22]
|American Iron and Steel Institute (2003): Characterization of Fatigue and Crash Performance of New Generation High-Strength Steels for Automotive Applications
|-valign="top"
|[23]
|Hill, S. I.: Standardization of High Strain Rate Test Techniques for Automotive Plastics Projects. UDRI: Structural Test Group. UDR-TR-2004-00016 (2004)
|-valign="top"
|[24]
|Society of Automotive Engineers Japan (SAE J) 2749 (2008): High Strain Rate Testing of Polymers
|-valign="top"
|[25]
|Stahl-Eisen-Prüfblätter (SEP) Technische Regel 1230 (2007-02): Ermittlung mechanischer Eigenschaften an Blechwerkstoffen bei hohen Dehraten im Hochgeschwindigkeitsdehnversuch
|-valign="top"
|[26]
|ISO 18872 (2007-02): Plastics – Determination of Tensile Properties at High Strain Rates
|-valign="top"
|[27]
|Borsutzki, M., Cornette, D., Kuriyama, Y., Uenishi, A., Yan, B., Opbroek, E.: Recommendations for Dynamic Tensile Testing of Sheet Steels. International Iron and Steel Institute (August 2005)
|-valign="top"
|[28]
|Kardelky, S.: Einfluss der Nukleierungsmittelart auf die Deformations- und Bruchmechanismen von medial beanspruchten PP/GF-Verbunden. Diplomarbeit. Martin-Luther-Universität Halle-Wittenberg (2002) (see [[AMK-Library]] under B 3-101)
|-valign="top"
|[29]
|Schröder, D.: Kombinierte Wirkung des Faservolumen- und Nukleierungsmittelgehaltes auf das mechanische Eigenschaftsniveau von PP/GF-Verbunden. Mater thesis. Martin-Luther-Universität Halle-Wittenberg (2003) (see [[AMK-Library]] under B 3-102)
|-valign="top"
|[30]
|ISO 527-1 (2019-07): Plastics – Determination of Tensile Properties – Part 1: General Principles
|-valign="top"
|[31]
|ISO 527-2 (2025-06): Plastics – Determination of Tensile Properties – Part 2: Test Conditions for Moulding and Extrusion Plastics
|-valign="top"
|[32]
|Schoßig, M., [[Bierögel, Christian|Bierögel, C.]], [[Grellmann, Wolfgang|Grellmann, W.]], Mecklenburg, T.: Mechanical behavior of glass-fiber reinforced thermoplastic materials under high strain rates. Polymer Testing 27 (2008) 893–900 DOI: https://doi.org/10.1016/j.polymertesting.2008.07.006
|-valign="top"
|[33]
|Schoßig, M.: Schädigungsmechanismen in faserverstärkten Kunststoffen – Quasistatische und dynamische Untersuchungen. Vieweg+Teubner / GWV Fachverlage GmbH, Wiesbaden (2010); see [[AMK-Library]] under B 1-21; [https://www.polymerservice-merseburg.de/fileadmin/inhalte/psm/veroeffentlichungen/Schossig_Promotion_Inhaltsverzeichnis.pdf Content as pdf]
|}

High-speed Tensile Test - Revision history