مدل سازي توزيع تنش در مت هاي بتني

چكيده انگليسي :

Stress Mdeling in Concrete Mat Samad Rahimizadeh sa rahiimizadeh@yahoo com Date of Submission 05 20 2012 Department of Textile Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Supervisor Mohammad sheikhzadeh m sh110 @cc iut ac ir Abstract Due to water shortage and its high value in arid and semiarid countries the prevention of water losses in transmission and distribution systems has always been considered as one of important principles in textile design In this regard the use of rigid and flexible coatings with technical characteristics and different costs has been paid attention by international organizations and researchers In this research it has been focused on introduction and analysis of textiles as concrete mold which is named incomat In the first chapter it has been described the classification characteristics and application of different types of incomats and their capabilities In the second chapter it has been described how to selecting filament filament fabric among the four types of fabrics using physical and mechanical experiments Then it has been mentioned to sewing type and the preparation of samples which have similar function with incomat type armor units during pouring of concrete The first coordinate axes x and y were drawn on samples with dimensions of 10 10 in order to measure deformation due to performing experiments Comparing results of humidity 32 and 52 show that with increasing the percent of humidity the rate of pressure and strain in samples was increased and in spite of increasing density due to decreasing humidity the viscosity increases It can be resulted that increase in viscosity has s direct relation with pressure In contrast the density has a reverse relation with the pressure Because of the same viscosity of the sample filled by concrete and the sample filled by soil and water mixture with humidity 32 it can be compared them with each other As mentioned previously the relation of strain increase between these samples is reverse In slope 45 strain in concrete sample is more than strain in another sample but with increasing slope to 65 and 90 strain in soil and water mixture of 32 increases and its amount is more than strain of concrete sample It can be caused from more cohesion of concrete related to soil and water mixture This cohesion avoids from applying more pressure to the textile Data resulted by experiments and shell equation gives similar shell shape for test specimens The result of maximum points derived from equations has high similarity to the deformation of specimens In concrete the coordinate of X and Y which has maximum transverse strain is shifted down by increasing slope This matter is justifiable by classic mechanics The following equilibrium equation is not true about soil behavior because soil has a soft body and its behavior is a function of ambient pressure There is a phenomenon in soil namely soil passive pressure This means that Soil mass is compressed by entering a Compressive stress to soil and it will indicate a lateral resistance via entering pressure This lateral resistance causes to centroid shifted to upward of the structure On the other hand the coordinate of maximum transverse strain is shifted upward of bag by increasing the rate of humidity at constant slope It can be resulted from higher humidity of soil related to optimum one with increasing humidity the volume occupied by the wet soil increases and coordinate of centroid will shifted upward Keywords incomat stress strain viscosity matlab software

رحيمي زاده، صمد

مدل سازي توزيع تنش در مت هاي بتني

لحاف بتني , كرنش , ويسكوزيته , نرم افزار متلب