Sharif Digital Repository

Masonry buildings are wide spread in Iran and some other countries . These buildings are highly vulnerable to seismic excitations if not constructed in accordance with engineering fundamentals . Thus it is necessary to retrofit these structures to flee from humanitarian and economical damages inflicted by earthquakes. One of the critical vulnerabilities of masonry buildings is due to transverse instability of it’s infills . Therefore to study out of plane behavior of these elements , an infilled frame is modeled and analyzed with ABAQUS , the results of which is in good congruence with the experimental one . In this model , stress distribution due to one way arching action in the confined... 

Performance of reinforced concrete frames is highly dependent on detailing of the joint connections between its members, such as beams and columns. To have a good structural behavior, joints must show ductile behavior and designed based on the philosophy of strong column-weak beam. In the case of sever lacking ductility, strength or even rigidity of the connections, or having a weak column-strong beam, in the existing structures, there is a need for seismic upgrading of the connection. There are several ways for seismic upgrading of this type of connections.In this research, using steel plates for seismic upgrading of Concrete Beam-Column connections subjected to axial and cyclic loads has... 

AS5U3G and AS7U3G are two prevalent types of alloy which are used in producing cylinder head. In this research AS5U3G alloy is studied. Gravity casting is one of the method of producing this part. Produced porosities in cylinder head casting process, cause leakage in this part. In order to solve this problem, some actions have been taken that we can divide them into quality operations improvement of melt and making changes in casts. The sampling is done in four levels to evaluate the gas porosity and shrinkage. In these levels, pressure and degassing duration and strontium's modifying in a fixed temperature have been evaluated. Based on reports by comparing density of relative samples, it... 

A high percentage of patients with lower extremities disability are consist of paraplegic patients, hemiparetic patients, spinal cord injuries and chronic stroke patients. Currently, a variety of methods are developed and being used for gait rehabilitation of these patients. Recently, beside physiotherapy and different types of exercises, gait trainers are used to help patients to obtain their walking abilities. The main goal of this work is to modeling, analysis and comparison of two different types of power transmission system for a gait training robot. A familiar gearbox and a cable mechanism for power transmission are studied and mechanical impedance and accuracy of systems in... 

Rehabilitation science has been proved that, in most cases, manipulation of injured body part, repeatedly, can help in returning the performance of that part. So robots can be useful for rehabilitation applications. Rehabilitation robots can record physical parameters such as position, velocity and force, so can play important role in developmentof making decisions on exercise types. Among the existing robots, cable-driven robots have specifications such as vast workspace, low cost, flexibility and light weight which make them suitable for rehabilitation applications.
The purpose of this research is kinematic design of a multi-link cable-driven robot for arm rehabilitation.In the most of... 

Performance of reinforced concrete frames is highly dependent on detailing of the joint connections between its members, such as beams and columns. To have a good structural behavior, joints must show ductile behavior and designed based on the philosophy of strong column-weak beam. In the case of sever lacking ductility, strength or even rigidity of the connections, or having a weak column-strong beam, in the existing structures, there is a need for seismic upgrading of the connection. There are several ways for seismic upgrading of this type of connections.In the last decade Fiber Reinforced Polymer (FRP) widely has been used to strengthening the reinforced concrete (RC) members. Most of... 

A high percentage of reinforced concrete buildings are not earthquake resistant because they are often designed based on old regulations, which do not satisfy the requirements of new earthquake codes. Construction weaknesses make buildings more vulnerable, and thus, different approaches are needed to strengthen structures to resist lateral forces. 3D Panel system brings together the best qualities of in-situ and precast systems and improves their shortcoming. It includes the advantages of precast systems, such as having relatively low labor costs, less waste material and machinery, reducing implementation time and improving quality control. At the same time, serious problems related to... 

Concrete structures may become weak and damage due to different reasons and need retrofitting or strengthening. Strengthening means increasing strength and resistance of members that injured to resist the design loads. The weakness of these structures may due to change in the design code provisions, administrative error, change in the usage of the building and damage caused by different events. In the last decade substantial research has been conducted on this field most of which were on the upgrading of RC beams under different loading. There are few studies in strengthening works of RC beams under static loads of torsion. Most researchers in this field have been used polymer fibers to... 

Poor maintenance of concrete bridges in the past years in Iran, caused serious damages, so most of them need rehabilitation. The majority of repaired members are exposed to repeated damage because compatibility of repair material to substrate concrete not considered as well as weather and loading conditions. This study attempts to improve the repair achievement and durability of concrete bridges. This investigation contains two phases: preliminary study and experimental phase. Preliminary study attends to detect different types of damages of concrete bridges and their causes along with their propagation. The next part of this study discusses about various types of repair materials. In... 

Knew is the biggest and most complicated joint in the body.Morever knew creat mobility must bear the weight of body and have a stability during static and dynamic activities.Knew is exposed different forces that force to around ligaments and soft fibers.After knew injuries, administration of aid is the important part of rehabilitation program.Rehabilitation robots with ability of accuracy and repetitive practices are good method for reducing time and energy of physiotherapist.At this thesis a 3 DOF Cartesian robot is designed and constructed for rehabilitation of knew that can do every practices for rehabilitation.Steps of designing and constructing of robot are based on movments of knew... 

Nowadays nearly 1% of the world population depends on wheelchairs for walking and movement. Due to harmful changes in human lifestyle, different diseases like stroke and problems in musculoskeletal system are increasing noticeably. Despite the fact that wheelchairs have recently been improved they have faced big problems like forcing people not to move and just sit for a long period of time. Wearable robots not only help these patients to rehabilitate their disabled organ and walk, but also have a significant mental effect on them.
The analysis of an exoskeletal orthosis designed for patients who have pain in one of their knees is presented. A mechanism for knee exoskeleton is analyzed... 

Based on special properties of metal dampers such as high energy dissipation, stable hysteric cycles and simple application, low cost, insensitivity to changes of temperature and ability to be substituted after occurring of earthquakes, they are being used for structures control. ADAS and SSD are two kinds of metal dampers which are connected to top of the chevron braces and under the middle of beams. When shear forces are applied, these dampers yield and enter the plastic zone. In Endurance Time (ET) method gradually intensifying acceleration functions are created in a manner that the linear and nonlinear response spectra of them, while being proportional to average of real earthquakes... 

With occurring severe earthquakes, damages of columns in RC buildings can lead to overall failure and collapse. So retrofitting of such columns that do not comply with the design requirements is necessary to prevent such phenomena. A variety of methods has been introduced so far for retrofitting. The key factors in determining the retrofitting methods are being economic and easily implemented in the design. Confining concrete columns with pre-stressed steel strips is a new technique that is simple and economic. Previous experimental experiments have shown that this method can enhance ductility and overall seismic behavior of such columns.
In the present study three and six story frames... 

One of the main reasons of being unable in doing routine jobs is the disability to attain and keep balance. This ability can be restored using rehabilitation techniques. A physiotherapist can be very helpful. This approach, however, apart from being very time consuming and expensive, needs quite a few physiotherapists. The physiotherapist will be prone to physical damages as well. This leads to improving therapy methods which do not require a physiotherapist. Using the rehabilitation balance devices can help solve the problem to some extents. If good device with reliable value system be developed, this device can be used without physiotherapist.
This project has been carried out to... 

Recognition of hand movements plays a key role in both human computer interaction and rehabilitation activities. This thesis focuses on hand pose estimation and motion tracking through a model-based stereo vision-based system. To allow for a complete 3D motion, initially a simple hand model with 20 landmark points was constructed and used to track its motion through a sequence of stereo images. Furthermore, a skeletal model representing the kinematical features of the hand was utilized to provide a meaningful hand motion and gesticulation. To evaluate and eventually recognize the performed hand motion, Kalman filter and Kalman smoother algorithms were implemented to evaluate the efficacy and... 

Today, people living in all over the world are faced with the arrival of Biomechanics and Human need of rehabilitation equipment is growing. Wearable robots have created a new field in service robots’ world. Unlike industrial robots, these robots are strongly interacting with humans. Physical interaction between humans and robots considered one of the exciting and challenging research topics. With attention to this issue, research projects have been started in the department of mechanical engineering of Sharif University of technology to design, manufacture and control a wearable robot with few degrees of freedom used in the lower joints. In this thesis, initially focused on the conceptual... 

Exoskeleton is a wearable active device used to augment human power in upper or lower extremities. The integration of robotic devices and conventional physiotherapy is becoming more and more acceptable worldwide. The main scope of this thesis is to design and develop a prototype of a light, low-cost and wearable robotic exoskeleton to rehabilitate the upper extremity in stroke patients at home. For this purpose mechanism of a wearable exoskeleton will be proposed compatible with upper extremity degrees of freedoms with minimum number of actuators which is constructed inexpensively to eliminate the demand of expensive and professional therapists. The conceptual design of such a system should... 

In recent years there have been a growing number of patients who are no more capable of leading an independent life, due to strokes, accident, or a variety of diseases. Thus, vast fields of physical rehabilitation have come into the attention of goverments and researchers. High costs of rehabilitation programs and their length on one hand, and the difficulties of commuting such patients to rehabilitation centers on the other hand, has made health department of various countries to look for alternative solutions.In this thesis, a computerized system has been designed and implemented in order to assess and guide patients in their rehabilitation excercises without needing any direct contact.... 

Rehabilitation usually involves physical therapy, occupational therapy and counseling for the patient's morale to help to restore his power and performance. Considering the economic outlook and the costs of rehabilitation methods and due to the increasing prevalence of stroke and the need to recover the patients in a short period, only the use of robotic systems opens the door to the medical community. Since a large rehabilitation robots designed and built and each been used according to their advantages and shortcomings. In this project, the major shortcomings examined and exoskeleton designed on two major features including portability and covering shoulder workspace. Shoulder movement was... 

A single-degree-of-freedom model is considered for flexible exercise bars based on the lumped-element approach. By considering the side segment of a flexible exercise bar as a cantilever beam with an equivalent mass at the free end, its free-vibration response and forced one under excitation of the grip of the flexible bar is written parametrically. Some experiments are performed on a specific flexible bar to obtain numerical values for the parameters in the model to have it quantitatively known. In the next step, simulation of the model results in the response of the flexible bar under a considered excitation. The response is imported into a multi-segment musculoskeletal software, AnyBody,...