Cumulative creep damage for polycarbonate and polysulfone

Polymer Engineering Science and Viscoelasticity

“…Step down loading creep to failure (yield) for polycarbonate (Zhang et al (1986). Reprinted with kind permission from Springer Science and Business Media) Clearly Robinson's life fraction rule is invalid for polycarbonate and the same was true for polysulfone though not shown here.…”

“…For a more complete discussion of the various cumulative creep damage rules as well as references to those given in Table 11.1 see Zhang et al (1986) and Dillard (1981). Zhang conducted extensive creep and creep to failure tests of polycarbonate and polysulfone for both single creep loads and multiple step-up or step-down creep loads as illustrated in Fig.…”

“…Fig. 11.21 Typical step-up and step-down creep tests (Zhang et al (1986). Reprinted with kind permission of Springer Science and Business Media) Fig.…”

“…Reprinted with kind permission of Springer Science and Business Media) Fig. 11.22 Creep to failure (rupture) for Polycarbonate for a single creep load (Zhang et al (1986). Reprinted with kind permission from Springer Science and Business Media)…”

Relationship between lifetime under creep and constant stress rate for polymer-matrix composites

“…Additionally the relationship obtained between the creep-rupture and constant stress rate (CSR) until failure is very simple. However for some materials LCD law is not applicable as Zhang and Brinson [7] verified for two different polymers using a two step creep loading condition. Yet that simple relationship, between the creep-rupture and CSR until failure, was independently obtained using two different cumulative damage formalisms which do not obey the LCD law.…”