'cracks occurred' is a correct and usable sentence in written English.
You can use it when you want to talk about something that happened, such as when a crack appeared in a wall or something. Example: Cracks occurred in the wall after the earthquake.
The deformation of the rebar increased at the cracking point when transverse cracks occurred in the reinforced concrete that was subjected to tensile stress.
The cracking loads were observed and recorded when initial cracks occurred while the corresponding displacements were named crack displacement.
All specimens exhibited increase of resistivity once cracks occurred between two electrodes.
Between 106 and 108 cycles a transition point is located, where both internal and surface initiations of cracks occurred.
More corrosion products accumulated at the steel surface where penetrating cracks occurred; whereas in the occluded cracks, the corrosion product was insignificant.
In addition, cracks occurred in the structural, heat sink part and propagated along the grains orientation of the deformed tungsten material.
An important conclusion is consequently reached that deep cracks occurred as a result of release of high ground stress including gravitational stress and tectonic stress.
Structural failure often follows the initiation of cracks occurring at corners, free edges or interfaces.
Thermal cracks occur on heat recovery steam generator (HRSG) casing, leading to heat loss.
Covering all such cracks lessens the potential for a problem but does not do away with it altogether, as new cracks occur all the time.
Based on fracture surface analysis, the premature cracks occur around big particles in grain boundaries lead to loss of elongation.
