"单轴向张力" can be translated as "uniaxial tension" in English.
Here, "uniaxial" means having or relating to a single axis, and "tension" refers to the pulling force transmitted axially by a string, cable, chain, or similar one-dimensional continuous object, or by the ends of a rod, truss member, or similar three-dimensional object. Together, "uniaxial tension" accurately describes the state of being subjected to tension along a single axis.