Influence of Temperature on the Mechanical Performance of Unidirectional Carbon Fiber Reinforced Polymer Straps

Abstract

The performance of pretensioned, laminated, unidirectional (UD), carbon fiber reinforced polymer (CFRP) straps, that can potentially be used for example as bridge deck suspender cables or prestressed shear reinforcements for reinforced concrete slabs and beams, was investigated at elevated temperatures. This paper aims to elucidate the effects of elevated temperature specifically on the tensile performance of pretensioned, pin-loaded straps. Two types of tests are presented: (1) steady state thermal and (2) transient state thermal. Eight steady-state target temperatures in the range of 24 °C to 600 °C were chosen, based on results from dynamic mechanical thermal analysis (DMTA) and thermogravimetric analysis (TGA). Transient state thermal tests were performed at three sustained tensile load levels, namely 10, 15, and 20 kN, corresponding to 25%, 37%, and 50% of the ultimate tensile strength of the pin-loaded straps at ambient temperature. In general, the straps were able to retain about 50% of their ambient temperature ultimate tensile strength (UTS) at 365 °C.

Fretting Fatigue Performance of Unidirectional, Laminated Carbon Fibre Reinforced Polymer Straps at Elevated Service Temperature

“…It is noteworthy that the T g onset, which is estimated by the intercept of the tangents below T g , appears at slightly lower temperatures, between 130 and 140 °C. The average T g value at peak tan δ for the four DMTA traces was 149.2 ± 1.4 °C, which is in agreement with previous measurements in [ 43 ], and within the anticipated range of 140 °C, which is suggested in the datasheet of the hot melt epoxy used herein [ 38 ]. Thus, the behaviour of the straps is expected to be rather elastic, as indicated in Figure 5 , where the storage modulus and tan δ traces show that, at 60 °C, the viscous part of the material response is negligible.…”

“…Thermocouple 4 was placed on the top pull rod outside the environmental chamber. The test set-up is presented in Figure 11 and is the same as the one used in [ 43 ]. The steady state thermal (SS) experiments involved two target temperatures, namely 24 (ambient) and 60 °C.…”

Material Monitoring of a Composite Dome Pavilion Made by Robotic Coreless Filament Winding

“…[ 35 ]. One parameter was the negative impact of an increased temperature [ 36 ] on the performance of the matrix and, therefore, the whole structure. Even minor effects could lead to structurally relevant issues.…”

Investigations on the Fatigue Behaviour of 3D-Printed Continuous Carbon Fibre-Reinforced Polymer Tension Straps

“…Previous experimental studies concerned strap specimens that were laminated using the same materials and a scaled-down geometry from those used in the above-mentioned network arch bridge [ 6 ]. These focused on the fatigue performance of the CFRP straps that were fretted against titanium and CFRP pins at room temperature [ 7 ] and elevated service temperatures [ 8 ], as well as on their thermomechanical behaviour at high temperatures that are representative of accidental load cases (i.e., fire) [ 9 ]. In the study presented herein, a new method of fabrication of CFRP straps based on 3D printing is explored in order to investigate its potential and durability limits against the conventional tape laying and out-of-autoclave lamination techniques that are currently the norm in composite manufacturing.…”