جستجوی مقالات مرتبط با کلیدواژه « semi-analytical solution » در نشریات گروه « مکانیک »

Todays, hydrogels have attracted many researchers due to their unique properties in responding to exterior stimuli and swelling-induced by water absorption. According to their reversible swelling, it is important to predict their mechanical response. The functionally-graded temperature-sensitive hydrogel is one of the most applicable materials in industry. Thus, to study the mechanical behavior of these materials, an energy density function is introduced which includes network stretch energy and mixing part. Then, considering functionally-graded properties along the thickness, bending of FG temperature-sensitive hydrogels is solved analytically under plane-strain assumption. Verifying the presented analytical procedure, the results are compared with outcomes of finite-element-method. To solve diverse problems by finite-element-method, UHYPER subroutine has been written and verified in free-swelling problem. Next, the radius, radial stress and tangential stresses are studied by both methods for FG temperature-sensitive hydrogels. Finally, according to the importance of factors such as semi-angle and bending curvature in the industrial designs, these factors are investigated by changing the temperature in range of 320 to 288. Results demonstrate the capability of these material to be implemented in sensors and actuators. In addition, the continuity of stresses field is the other reason of utilizing FG hydrogels, while the multi-layer hydrogels do not have continuous stress fields.

The accurate and efficient design of the bilayer sensors and actuators made of hydrogels are of crucial importance. In this work, a semi-analytical method is developed to solve the swelling induced bending of hydrogel bilayer under plane strain condition. The bilayer consists of a neutral incompressible elastomer layer attached to a hydrogel layer. The interface of two layers is assumed to be perfectly bonded. Moreover, the plotted problem is simulated using Finite Element Method (FEM) employing UHYPER subroutine in ABAQUS software. Several cases are solved to demonstrate the validity and performance of the proposed semi-analytical method. A good correspondence between the presented method and the finite element method is observed. The deformation and the stresses inside the layers are presented for various material parameters employing both the developed semi-analytical formulation as well as the finite element method. Finally, the effect of density of cross-link in hydrogel polymer network on curvature is also investigated.