Multiaxial

Multiaxial is an adjective used to indicate the involvement of more than one axis, direction, or dimension in a system or analysis. The term is used in fields as diverse as engineering, materials science, and psychology to describe complexity that cannot be captured along a single axis.

In engineering and materials science, multiaxial loading refers to stresses acting on a component from multiple directions simultaneously, such as axial, torsional, and shear stresses. Analyzing multiaxial stress states is essential for designing components that must tolerate complex loading and for estimating fatigue life. Common approaches include principal stress analysis and criteria such as von Mises or Tresca to predict yielding under multiaxial conditions.

In clinical psychology and psychiatry, multiaxial assessment historically referred to a framework in the DSM-IV-TR that categorized disorders and related conditions across five axes: I through V. Axis I encompassed clinical disorders; Axis II covered personality disorders and mental retardation; Axis III documented medical conditions; Axis IV captured psychosocial and environmental problems; Axis V provided a global assessment of functioning. With DSM-5, published in 2013, the multiaxial system was eliminated in favor of a single diagnostic axis and separate functioning measures. The term multiaxial remains a historical reference in contemporary practice.