Articular cartilage plays a central role in joint function by enabling load transmission and low-friction motion under complex mechanical conditions. Its multiphase and structurally heterogeneous nature makes comprehensive experimental characterization challenging, motivating the use of computational models that must be rigorously calibrated and validated against mechanical experiments. This work aims to enhance the predictive capabilities of finite element simulations by integrating mechanical experiments, sensitivity analyses, parameter identification, and validation within a well-established biphasic constitutive model for articular cartilage [1]. Sensitivity analyses revealed distinct parameter dominance depending on the loading regime, with fiber stiffness governing tensile behavior and matrix and permeability parameters controlling compressive response. Parameter fitting for uniaxial extension and confined compression achieved excellent agreement with experimental data and successfully predicted independent biaxial loading conditions. Remaining discrepancies highlight the importance of experimental variability and boundary conditions. The validated biphasic model offers a robust tool for analyzing cartilage mechanics and supports future efforts aimed at improving strategies for cartilage treatments. [1] Pierce, D.M., Unterberger, M.J., Trobin, W., Ricken, T., Holzapfel, G.A., A microstructurally based continuum model of cartilage viscoelasticity and permeability incorporating measured statistical fiber orientations, Biomechanics and modeling in mechanobiology, 15 (1), pp. 229–244. 2016.