نوع مقاله : مقاله پژوهشی
نویسندگان
1 دانشکده مهندسی مکانیک، دانشگاه تهران، تهران، ایران
2 دانشگاه تهران*مهندسی مکانیک
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
In this paper, by using the theory of continuum damage mechanic and experimental methods, damage evolution is investigated. There are various experimental and theoretical methods for measuring the damage in materials. the experimental methods can be categorized in two type, i) destructive methods like analysis of chord modulus variation, and the ii) non-destructive methods like micro hardness or macro hardness evaluation. In this paper at the first, true stress - true strain diagram of material using the simple tension test and chord modulus variation using repetitive loading - unloading test is obtained. For measuring plastic strain, grids are etched on the tension sample by using electroetch device. And then by measuring major ellipsoid diameter on the broken sample and comparing with the preceding circle, plastic strain at different points is specified. At specified points of the sample, the micro hardness and the macro hardness are measured. Using the data of these three experimental methods, the corresponding damage is evaluated and the corresponding charts are plotted. Finally the evaluated damage by these three methods is compared. It is observed micro hardness and loading-unloading[1]tension test have relatively similar progress, but macro hardness progress had a significant difference with these two methods. It’s also observed, average of three methods is close to micro hardness method rather than two other.
کلیدواژهها [English]
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