The phrase "are frequently divided" is correct and usable in written English.
It can be used when discussing how something is often separated or categorized into parts or groups.
Example: "In academic research, subjects are frequently divided into various sub-disciplines for more focused study."
Alternatives: "are often split" or "are commonly categorized".
These diseases are frequently divided into those that result in arterial occlusion (blockage) and those that are nonocclusive in their manifestations.
Macromolecular crystallization efforts are frequently divided into a search phase, during which approximate conditions are sought, and an optimization phase, when the approximate conditions are optimized to yield crystals of sufficient quality for diffraction work.
Males are regarded as superior to women in most activities; the elders are respected as repositories of both secular and spiritual wisdom; and people, such as cousins who may be of the same genealogical distance, are frequently divided into "marriageable" and "nonmarriageable" groups, with consequent differences in their interpersonal behaviour.
If you have a board where votes are frequently divided and contentious, then ultimately you have a serious problem at the company itself.
xxxi, 353 pages, ISBN 978-90-481-9621-0 e-ISBN 978-90-4810.1007/978-90-481-9622-7.90-481-9622-7. Analyses of Chinese rangeland management are frequently divided on the identification of problems and solutions based on the nationality of the author.
Biomarkers are frequently divided into two different categories, depending on the number of substances/groups of substances they are known to respond to: General (integrative) biomarkers that respond to several classes of toxic substances and, frequently, also to other types of stressors.
Reaction to Lincoln's address was frequently divided along political lines.
Later, Ms. Weir called the unanimous vote by a board that is frequently divided along partisan lines "an historic moment".
The gait cycle is frequently divided into two distinct phases, stance and swing, which can be accurately determined from ground reaction force data.
While comics are often the work of a single creator, the labour of making them is frequently divided between a number of specialists.
Minority voters were frequently divided among crowded fields of black candidates, leaving room for well-financed white candidates often backed by conservative business interests to win by narrow majorities, Bositis said.
