  Among two-dimensional (2D) materials, transition metal dichalcogenides (TMDs)
stand out for their remarkable electronic, optical, and chemical properties. In
addition to being variable bandgap semiconductor materials, the atomic thinness
provides flexibility to TMDs. Therefore, understanding the physical properties
of TMDs for applications in flexible and wearable devices is crucial. Despite
the growing enthusiasm surrounding two-dimensional transition metal
dichalcogenides (TMDs), our understanding of the mechanical characteristics of
molybdenum ditelluride (MoTe$_2$) remains limited. The mechanical properties of
MoTe$_2$ deteriorate in the presence of pre-existing cracks or vacancy defects,
which are very common in grown TMDs. In this study, the fracture properties and
crack propagation of monolayer molybdenum ditelluride (MoTe$_2$) sheets
containing pre-existing triangular cracks with various vertex angles are
investigated by performing molecular dynamics (MD) simulations of uniaxial and
biaxial tensile loading. Due to pre-crack length, angle, and perimeter
variations, monolayer MoTe$_2$ with pre-existing cracks underwent considerable
changes in Young's modulus, tensile strength, fracture toughness, and fracture
strain values. We have found that the pre-cracked MoTe$_2$ is more brittle than
its pristine counterpart. Regulated alteration of pre-crack angle under
constant simulation conditions improved the uniaxial mechanical properties.
Similarly, regulated alteration of the perimeter of the pre-crack resulted in
improved biaxial mechanical properties. This study contributes to the
foundational knowledge for advanced design strategies involving strain
engineering in MoTe$_2$ and other similar transition metal dichalcogenides.
