['However', ',', 'due', 'to', 'the', 'stiffness', 'of', 'the', 'linear', 'system', 'at', 'high', 'values', 'of', 'the', 'bulk', 'modulus', ',', 'the', 'penalized', 'formulations', '(', 'classic', 'penalty', '/', 'weakly', 'penalized', ')', 'exhibit', 'deteriorated', 'nonlinear', 'convergence', '.']