Effects of Temperature on the Bearing Strength of CF/Epoxy Pinned Joints

Abstract

Pinned joint bearing tests are conducted at room temperature (25 C) and at high (150 C) and low (À100 C) temperatures for CF/epoxy quasi-isotropic laminates cured at 180 C with two stacking sequences, namely, [0/45/À45/90] 3S and [90/À45/45/0] 3S . Then, the evolution of microscopic damage as a function of load is examined by using an optical microscope. This article presents an original set of experimental data on the bearing strength of CF/epoxy pinned joints at high and low temperatures, as well as room temperature, while the previous studies did not cover the wide range of temperatures. Moreover, a technique for dynamically monitoring the load is developed to obtain the damage at the maximum load. The critical damage has not been distinguished from the secondary ones in the previous literature. It is found that the bearing failure of a pinned joint is composed of various damages depending on environmental temperatures; further, the strength of the pinned joint is closely related to the compressive kinking failure of all the inner 0 layers. Other characteristic features of the damage evolution at each temperature are discussed in detail.

Investigating bearing strength of pin-loaded composite plates in different environmental conditions

“…On the other hand, it fails catastrophically in both the tensile and shear-out modes. 15 Failure types are determined by observing the failure regions. Four different modes of failure were observed after tensile tests in this study.…”

Effects of temperature on the response of composite bolted joints

“…Sometimes a semi-circular-hole specimen [22][23][24]27,28 is also adopted. The test method is schematically shown in Fig.…”

“…After one hour at the testing temperature, when the temperatures of all the thermocouples remain steady within 2°C of the desired testing temperature, mechanical loading starts. 9.2.2 Load-displacement response [22][23][24]28 The typical load-displacement curves of a pin joint obtained at LT, RT and ET are shown in Fig. 9.2 , where a semi-circular-hole specimen was loaded.…”

“…Though there are various literature items on mechanical Hirano et al 22 performed the bearing test of a semi-circular notched pin joint of T800/3631; they obtained the effects of various temperatures on the strength and load-displacement curve and investigated the microscopic features of damage and their three-dimensional (3D) distribution. Further, Hirano et al 23 investigated the microscopic damage evolution under LT, RT and ET at various load levels and verifi ed that the critical damage is always the compressive kinking of 0° inner layers by using a technique of dynamic monitoring of load. Hirano et al 24 also presented the results for a 1.2 Nm torque bolted joint.…”

“…Further, Hirano et al 23 investigated the microscopic damage evolution under LT, RT and ET at various load levels and verifi ed that the critical damage is always the compressive kinking of 0° inner layers by using a technique of dynamic monitoring of load. Hirano et al 24 also presented the results for a 1.2 Nm torque bolted joint. Vieille et al 25 performed the bearing test under RT and ET120 for bolted T300 3K 5HS/pps (fi ve harness satin carbon cloth reinforced thermoplastics polyphenylenesulfi de) and obtained less strength compared to the RT case.…”