Sharif Digital Repository

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... 

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... 

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... 

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... 

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... 

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... 

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... 

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... 

Maintaining balance is an essential need for human. This ability is sometimes lost or weakened due to reasons such as muscle weakness, vision problems, and neuromuscular problems. It was difficult to accurately measure balance parameters in the past because it needs expensive equipment and the presence of a physiotherapist. In new clinical setups, accurate measurements of balance quality have become possible using advanced devices. These devices are also used to provide therapeutic exercises to improve the balance condition. One of the most famous products in this area is the Biodex balance SD. The cost of this device, however, is high and it is for research and clinical use. The purpose of... 

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,... 

Human motion capture is frequently used to study rehabilitation and clinical problems, as well as to provide realistic animation for the entertainment industry. IMU based systems as well as Marker based motion tracking systems are of most popular methods to track movement due to their low cost of implementation and lightweight. Results of IMU leads to unacceptable drift errors while marker based systems are Drift-free. Also, unlike cameras, IMUs are suitable for long-distance motion capturing. Based on the complementary properties of marker based systems and the inertial sensors, in this work, an Extended Kalman Filter approach was developed to fuse the data of two IMUs and a single camera... 

Quantitative motion quality evaluation has been always of much significance for CVA patients, especially the HCP ones. The purpose of the present study is to introduce and analyze the efficiency of a novel index, namely “Consumed Energy Index”, for evaluating the quality of the motions performed by HCP patients. For this purpose, Firstly, a Musculo-Skeletal model of the human arm was provided on Matlab and OpenSim softwares, with four DoFs: three DoFs at shoulder and one DoF at elbow joint as well as eight muscles. The muscles are in pairs of flexor-extensor at each DoF. The model is capable of receiving Cartesian trajectories for joints and solving inverse kinematics and dynamics to obtain... 

A total of twenty-four reinforced concrete arches with dimensions of 110 × 30 × 10 cm were casted, fabricated and tested. There are three variables, including: height to span ratio, longitudinal reinforcement ratio and arrangement and number of FRP layers.Based on results, with increasing height to span ratio, the efficiency of FRP strengthening method decreases. It is due to the fact that FRP materials inherently behave better in tension. From another point of view, in lower arches (L group) extrados bonding technic has better effect on increasing peak load of the arches, while in higher ones (H group) intrados bonding is discerned as the best method of strengthening. This paradoxical... 

Each year, from %30 to %60 of the elderlies fall down. %10 to %20 of these incidents result in severe injuries. Aging along with stroke can possibly damage body balance system temporarily or permanently. Therefore, human body balance system improvement and treatment seems necessary. Physical therapy methods relying on assistance require not only physiotherapist presence, but also considerable amount of money and time for both patient and physician. Thus, novel rehabilitation methods that do not require physiotherapist presence can help patients greatly. To do so, an apparatus has been designed and fabricated at Sharif University of technology. This apparatus can produce the active... 

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... 

Rehabilitation of disabled people faced some fundamental changes during past two decades. In the past, the main goal was to reduce the negative effects of disability but now various approaches are used to restore limb movement. As these people own weak muscles due to their lack of physical training, they need Intensive physiotherapy exercises to retrieve their body strength. As a consequence, rehabilitation centers are more willing to employ new ways. These new ways exert less physical pressure on physiotherapists. It helps them to be immuned from diseases like Arthritis or back injuries that is common in such servises. So the movement assisting devices can be of a great help for both... 

In this project, two bidirectional loadcell are designed and fabricated to be installed on a walker. Then upper extremities’ forces and moments have been obtained. Results can be used for rehabilitation purposes in Spinal Cord Injuries and Cerebral Palsy cases. The method used in this project is as follows: First, since the commercial multidirectional loadcells are too expensive, the loadcell (and an appropriate electronic board) are fabricated. Ultimately, a complete gait analysis by means of VICON motion analysis and using inverse dynamic method has been held to measure upper extremities’ forces and moments in the wrist, elbow and shoulder. The results for a person with Spinal Cord Injury... 

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...