در دنیای پیشرفته امروز، به ویژه در حوزه های مهندسی مکانیک و صنایع هوافضا، کامپوزیت ها به دلیل ویژگی منحصربه فرد استحکام بالا در کنار وزن کم، جایگاه برجسته ای یافته اند. با این حال، رفتار پیچیده این مواد، تحلیل دقیق و ابزارهای پیشرفته ای را برای مدل سازی و پیش بینی آسیب های ساختاری آن ها می طلبد. پژوهش حاضر با بهره گیری از ترکیب مدل های چندمقیاسی مزو-ماکرو و مفاهیم مکانیک آسیب پیوسته، رویکردی نوین برای تحلیل و ارزیابی خرابی در ساختارهای کامپوزیتی ارائه می کند. این مطالعه از چارچوب مدل های چندمقیاسی شبه همزمان بهره می گیرد که با استفاده از روش های پیشرفته شبیه سازی المان محدود و ابزارهای پردازش تصویر، امکان تحلیل جامع ترک خوردگی زمینه و شکست الیاف را فراهم می سازد. افزون بر این، زیربرنامه ای مبتنی بر مفاهیم مکانیک خرابی پیوسته در نرم افزار المان محدود میتوان توسعه داد که قادر باشد تکامل آسیب ها، از جمله پیشرفت ترک ها، شکست الیاف و پیش بینی بار نهایی شکست سازه های کامپوزیت را به صورت پیش رونده تحلیل کند. از سوی دیگر، به کارگیری روش های هوش مصنوعی، به ویژه در پردازش تصویر، سبب کاهش زمان و هزینه های محاسباتی شده و دقت تحلیل های مکانیکی را به طرز چشمگیری افزایش داده است. این رویکردهای چندمقیاسی هوشمند نقشی کلیدی در بهینه سازی طراحی و پیش بینی دقیق مکانیزم های خرابی ایفا می کنند. این روش ها، به ویژه در کاربردهای پیچیده و حساس هوافضایی، ابزارهای مؤثری برای ارتقای عملکرد و قابلیت اطمینان ساختارهای کامپوزیت ها به شمار می روند.

The progressive motivation around improvement of process plants has led to the development of numerous planning and scheduling optimization formulations. The present article has provided a new and extended modeling scheme for determining an optimal scheduling production of mixed continuous-batch working plants. Although, several models have been presented for scheduling of batch plants, less attention has been paid for mixed batch and continuous ones. The novelties in the present paper cover this important issue through the extension of previous works of associated researchers with emphasis on materials intervention in storage tasks.

The application of continuum robots with flexible mechanical structures is becoming more widespread in the aerospace. These types of robots have recently used to inspect aircraft fuel tanks and space probes. In this paper, the kinematic behavior and working space of a one-segment continuum robot with a tendon mechanism is studied. The theory for kinematic analysis is the fixed curvature method which is the most effective for analyzing continuum robots especially in the case of weightlessness. Also, the amount of tension and bending of the secondary backbones of the continuum robot in the one-dimensional and three-dimensional were investigated as a time dependent functions. Results showed the rate of change of link lengths is about 39. 1% increase of back link, and 17. 8%, and 21. 2% decrease in others with an initial length of 40 mm. Based on this results, it is possible to estimate the amount of tension and bending over a certain period for different types of materials. Additionally, the error of reaching to target point in the obtained optimal values of bending and rotation angles, equal to 67. 35 and-40. 89, was almost zero which shows the very high accuracy of model. Also, the results of the working spacecover the surface of the sphere of the working space with an accuracy of 1 mm, The obtained results increase accuracy of robot moving in environments with complex structures and limited spaces. The proposed model can be used as a base for continuum multi-part robots.

In machine dynamics, the tool point frequency response functions (FRFs) are employed to predict the stable machining conditions. A combined analytical-experimental substructuring procedure is proposed to determine the tool point FRFs usable for different holder-tool configurations. Contact interface of holder-spindle and tool-holder is modeled using translational and rotational springs and dampers spread in the length of contact surface. These joint parameters are defined using finite element method. This enables the analyst to introduce the contact stiffness and damping in more detail taking into account variations of normal pressure in the tool-holder and holder-spindle joints. The dynamic analysis of the holder is done using Timoshenko beam theory by chebyshev method. The tool dynamics is modeled by Euler-Bernoulli beam theory using the method of equivalent diameter. For the purpose of shifting the tool stability lobes to a higher level, tool damping parameter is modified by internal frictional damper and the effect is analyzed by analytical methods and experimental study. New method for continuous dynamic coupling is presented. The method employs the measured spindle-machine FRFs and analytical models of the tool and holder to predict the tool tip FRFs. An experimental case study is provided to demonstrate the applicability of the proposed method.

Existing location allocations approaches do not take into consider the changeability nature of the world. This happens, whereas the most location allocation problems face time changing parameters. The change of these parameters can be foreseen sometimes so they should be token into consider in location allocation by modeled approaches. This paper has formulated the location allocation problem of p-median type dynamically and proposed an approach for solving dynamic location allocation and resource allocation problems based on artificial intelligence. A sample problem of NP-Complete type has been propounded and solved in dynamic and static modes in order to evaluate performance of the proposed approach. The implementation results has verified performance of the proposed method and dynamic location allocation approaches in respect to static ones for solving location allocation problems using change of demand model in time.