Jay

From your last post it seems you consider the modal analysis must always start the math over the operating state. Despite your remark about lifted-off supports is correct, such statement is not particularly true for snubbers case because they are devices intended to not participate to operational cases but to dynamic cases ( mathematically within modal analysis, as well). For dynamics, K matrix must consider the snubbers existence. In fact Caesar just follows in calculation the physical reality, this is the accurate statement.