Transient Effects of Applying and Removing Strain on the Mechanical Behavior of Rubber

Abstract

For viscoelastic materials, the relationship between stress and strain depends on time, where the applied strain (or stress) can be expressed as a step function of time. In the present work, we investigated two temporary effects in the response of viscoelastic materials when a given strain is applied and then removed. The application of strain causes a stress response over time, also known as relaxation. By contrast, recovery is the response that occurs following the removal of an applied stress or strain. Both stress and relaxation constitute transient stages of a viscoelastic material exposed to a permanent force. In the current work, we performed several experimental tests to record the recovery in response to the total or partial removal of the strain. By observing and analyzing the mechanical response of the material to strain, we deduced that recovery is a procedure not only related to creep but also to relaxation. Hence, we created a model that simulates the behavior of viscoelastic materials, contributing to the prediction of relevant results concerning different conditions.

Elimination Of The Mullins Effect For Four Rubbers

“…A phenomenon associated with stress softening, the Mullins effect, must be accounted for to meet the requirements of the present research [2,4,6,8]. Namely, when a rubber sample is extended from its virgin position, unloaded, and then reloaded again, the required stress upon reloading is less than that needed at the first loading for strains up to the maximum strain reached on the initial loading.…”

“…It is obvious that several factors affect the stress softening phenomenon, as it is a damage procedure that occurs in the molecules' chains. Apart from materials whose consistency vary, some other factors are related to temperature, strain value or speed that the crosshead is moving in order to deform the griped sample [5][6][7].…”

Evaluating the effect of environmental conditions on high compressive strain rates in unfilled and filled neoprene rubbers

“…1 Hence, it can be adopted in a wide application range relative to engineering, automotive, coating, and aquatics. 2,3 However, the latest application innovation requires even more enhanced durability and stiffness of rubbers. Thus, the filled rubbers were fabricated to satisfy those requirements.…”

Fem Predictions Of Viscoelastic Behavior Of Natural Rubber For Higher Speeds

“…Elastomers exhibit viscoelastic behavior that can be examined by performing several experimental tests where material samples are subjected to a desired strain level and then is held constant for some time. The stress response to those causes is the loading and relaxation for the corresponding time periods [7][8]. Simulating the experimental results amplifies the prediction of rubbers' behavior in different conditions and hence, the quicker and simpler the procedure becomes [5][6][7]9].…”

“…The stress response to those causes is the loading and relaxation for the corresponding time periods [7][8]. Simulating the experimental results amplifies the prediction of rubbers' behavior in different conditions and hence, the quicker and simpler the procedure becomes [5][6][7]9].…”