Quasistatic Material Testing

Determination of mechanical properties by using universal testing facilities

Structural compon­ents are exposed to mech­an­ical stress, which requires a compre­hens­ive char­ac­ter­iz­a­tion of the mech­an­ical prop­er­ties. Thus compon­ents can be tailored for their inten­ded use. We can determ­ine the follow­ing import­ant key figures for the designer.

  • stiff­ness, strength, tough­ness
  • damage toler­ance against cracks, notches and mater­ial defects
  • mech­an­ical beha­viour at differ­ent temper­at­ures
  • relax­a­tion, creep, hyster­esis

All tests are performed on a calib­rated univer­sal test­ing device in accord­ance with accep­ted stand­ards (DIN, ASTM, EN and ISO). The force-displace­ment diagrams are recor­ded using a PC and analyzed with soft­ware specially developed for this purpose.

Temperature ranges
for tensile tests -150 °C to +1000 °C, at -196 °C (LN2) and at -269°C (LHe)
for compres­sion tests -150 °C to +800 °C, at -196 °C (LN2) and at -269°C (LHe)
for bend­ing tests -150 °C to +1100 °C, at -196 °C (LN2) and at -269°C (LHe)
frac­ture mech­an­ics -150 °C to +1100 °C, at -196 °C (LN2) and at -269°C (LHe)
Quasistatic Material Testing_1Tensile and compression tests
  • Determination of mech­an­ical para­met­ers
  • Investigation of temper­at­ure beha­vior
  • Force sensors for differ­ent force ranges avail­able
  • High-resol­u­tion, non-contact extens­o­meter in use
Bending tests
  • three-point bend­ing tests on injec­tion molded parts and fibre-rein­forced compos­ites
  • Interlaminar shear strength of long fiber-rein­forced plastics
  • Four-point bend­ing test of compact mater­i­als and sand­wich struc­tures

Quasistatic Material Testing_2Varying moment curve at 3-point- and 4-point-bend­ing test
(M=bending moment, IA=span lenght, Lv=effective span)

Determination of the critical stress intensity factor

Quasistatic Material Testing_3Force-crack open­ing curve
Crack growth starts at fors FQ

  • char­ac­ter­iz­a­tion of damage toler­ance to defects
  • determ­in­a­tion of the E-modu­lus
  • by normal­iz­a­tion to the sample geometry, mater­ial-specific para­met­ers are provided
Interlaminar fracture toughness
  • prob­ab­il­ity of defects in fibre-rein­forced plastics is higher than in homo­gen­eous plastics
  • the criteria of linear elastic frac­ture mech­an­ics are not valid for fibre-rein­forced plastics
  • energy release rate char­ac­ter­izes the strength of the mater­ial

Quasistatic Material Testing_4