Carbon/glass hybrid rods exhibit superior tensile strength, low weight, and exceptional corrosion resistance. However, rod splitting presents a considerable challenge to their practical applications, impeding widespread acceptance. A strength prediction model for carbon/glass hybrid rods was created utilizing a multi-mode damage constitutive material model. Tensile experiments were conducted to validate the simulation model, elucidating stress distribution patterns and creating progressive damage evolution laws to clarify failure causes, thus offering theoretical support for the construction of high-strength rods. The results indicated that: (1) Experimental data indicated an average tensile load of 452.4 kN, with failure resulting from brittle fracture and interface debonding; (2) The simulated ultimate tensile load was 439.2 kN, deviating by 3% from experimental values within acceptable engineering accuracy limits; (3) As displacement increased from 0.3 mm to 0.7 mm, von Mises stresses in the coating layer, −40° winding layer, 40° winding layer, and core layer rose from 96.4, 62.2, 43.6, and 199.2 MPa to 229.6, 141.6, 111.1, and 472.4 MPa, respectively; (4) The primary forms of damage were interface debonding, matrix cracking, matrix extrusion, fiber extrusion and fiber fracture. The weak interface strength and asynchronous deformation between the carbon-fiber core layer and the glass-fiber cladding layer facilitated interface slip, leading to the premature failure of the winding layer due to a rapid decline in interface load transfer, ultimately resulting in interlayer splitting failure of the rod.

Composite sucker rods are widely used in oil fields because of light weight, high strength, and corrosion resistance. Bonded technology becomes the primary connection method of composites. However, the joints with composite sucker rods are prone to debone and fracture. The connected characteristics are less considered, so the failure mechanism of the joint is still unclear. Based on the cohesive zone model (CZM) and the Johnson-Cook constitutive model, a novel full-scale numerical model of the joint with composite sucker rod was established, and verified by pull-out experiments. The mechanical properties and slip characteristics of the joint were studied, and the damaged procession of the joint was explored. The results showed that: a) the numerical model was in good agreement with the experimental results, and the error is within 5%; b) the von Mises stress, shear stress, and interface stress distributed symmetrically along the circumferential path increased gradually from the fixed end to the loading end; c) the first-bonded interface near the loading end was damaged at first, followed by debonding of the second-bonded interface, leading to the complete shear fracture of the epoxy, and resulted in the debonding of the joint with composite sucker rod, which can provide a theoretical basis for the structural design and optimization of the joint.