Diagnostics of steel structures with the dynamic non-destructive method

The method of the assessment of steel structures mechanical properties is considered with the nondestructive test by conical indentation. The nondestructive evaluating of the steel mechanical properties in real structures is widely spread in many applied problems. Dynamic indentation method is one of the most effective because of compatibility and accuracy. For this purpose, the static and dynamic problem of axisymmetric elastic-plastic truncated cone indentation is solved, and the results are compared with finite element analysis and experimental data. The method of nondestructive evaluating of mechanical characteristics is suggested and devise of the realization of the method is tested at real structures. The method is tested on steel railway bridges that are being operated for more than 60 years. As a result, zones with lower strength values were identified, and recommendations for strengthening the design were given

The non-stationary dynamic of a beam under the elastic-plastic impact of a conical indenter

The problem of impact interaction of a conical indenter with the surface of a steel beam under elastic-plastic deformation is considered. The analysis of the dynamic reaction of the beam to the impact is considered analytically and numerically. The analytical solution is based on the phenomenological model of conical indentation and the solution of wave equations of beam dynamics at impact. The numerical study of the indentation process was carried out using the ANSYS software. The dynamic response of the beam is analyzed for different geometric parameters and different values of strength characteristics. Such tasks are widely used in construction practice in the implementation of non-destructive methods of assessing the mechanical characteristics of structures

Metal structures diagnosis by truncated cone indentation

The method of the steel structures diagnosis is considered with nondestructive test by truncated cone indentation. Recently, great interest in the nondestructive evaluating of the steel mechanical properties at real structures is developed in many applied problems. Dynamic indentation method is one of the most effective because of compatibility and accuracy. For this purpose static and dynamic problem of axisymmetric elastic-plastic truncated cone indentation is solved and the results are compared with finite element analysis and experimental data. The method of nondestructive evaluating of mechanical characteristics is suggested and devise of the realization of the method is tested at real structures

Non-destructive test of steel structures by conical indentation

The problem of mechanical properties measurement of steel structures by non-destructive method of impact cone indentation is considered. The method is based on analytical solution and experimental data of a problem of impact indentation by cone into elastic-plastic half-space. Non-destructive dynamic indentation method is one of more efficient for mechanical properties assessment because of compact instrument that makes it possible of measuring at any point of structure. The scheme of impact indentation was considered and the problem of elastic-plastic impact is solved. The device with a computer way of information processing was created and tested for determining the characteristics of the existing structures. The method was adopted and tested on bridge structures, butt welded joints, civil engineering structures and others

Complex method of defects diagnostics in underground structures

The article presents a comprehensive method for diagnosing underground structures using the example of an underground pedestrian crossing located in Rostov-on-Don. The problem of assessing the condition of buildings and structures is very relevant at all stages of the life cycle. There is a special need for continuous monitoring of bearing structures for many buildings with critical applications especially if reliability of which determines the life and health of people. This work considered complex method included geodetic research, geological study of the state of sub-soil, analysis of state of steel and reinforced concrete structures, vibro diagnostics of load-bearing structures under dynamic technogenic impacts and an assessment of the mechanical characteristics of steel and reinforced concrete structures in order to develop a conclusion on the overall state of the transition and the possibility of its further operation. Analysis of the response from arbitrary non-stationary effects on structural elements is carried out on the base of the calculated spectrum of reference impacts

Attitude sensors relative angular misalignment estimation in integrated navigation systems

When using modern navigation systems as part of an on-board system, the navigation task can be solved in several ways: using positional, velocity and angular corrections, and systems using measurements of various physical nature—radio, such as short-range and long-range navigation radio systems, GLONASS/GPS satellite global navigation systems, optical—celestial navigation systems—can operate as correctors. The best performance of INS and its sensors (gyroscopes and accelerometers) errors estimation can be obtained when all types of correction are implemented simultaneously. At the same time, it is particularly difficult to implement correction according to attitude parameters due to the fact that the measuring axes of the INS and correctors may not match on board of moving objects. Such a mismatch is commonly called relative angular misalignment. The paper considers a possible approach to the attitude sensors relative angular misalignment estimation in integrated navigation systems (NS), carried out in motion when the NS is in operating mode

Complex method of defects diagnostics in underground structures

The article presents a comprehensive method for diagnosing underground structures using the example of an underground pedestrian crossing located in Rostov-on-Don. The problem of assessing the condition of buildings and structures is very relevant at all stages of the life cycle. There is a special need for continuous monitoring of bearing structures for many buildings with critical applications especially if reliability of which determines the life and health of people. This work considered complex method included geodetic research, geological study of the state of sub-soil, analysis of state of steel and reinforced concrete structures, vibro diagnostics of load-bearing structures under dynamic technogenic impacts and an assessment of the mechanical characteristics of steel and reinforced concrete structures in order to develop a conclusion on the overall state of the transition and the possibility of its further operation. Analysis of the response from arbitrary non-stationary effects on structural elements is carried out on the base of the calculated spectrum of reference impacts

Dynamic response of a plate laying on elastic base during the impact of a conical indenter

The article presents an analytical and numerical study of a dynamic conical indentation during impact process. The circular plate laying on the elastic base is subjected to impact load by the conical indenter. Local deformations in imprint zone are considered as elastic-plastic and general plate deformations are only elastic. According to Timoshenko method, the general plate displacement is considered as the sum of the elastic-plastic displacement of the indenter and the elastic displacement of the plate at the impact point. The solution is constructed with Fourier transforms and the Green function of the dynamic process is obtained. The numerical study of impact indentation is received by FEM method. The dependences of displacements, velocities, and accelerations of the plate on time is obtained during impact. The experimental data obtained with the special device is compared with the results of the numerical analysis. The method of an assessment of the mechanical characteristics of steel is proposed on the basis of the research. Analysis of the dynamic response and non-stationary effects on structural elements is carried out on the base of the calculated impact process

Non-destructive test of steel structures by conical indentation

The problem of mechanical properties measurement of steel structures by non-destructive method of impact cone indentation is considered. The method is based on analytical solution and experimental data of a problem of impact indentation by cone into elastic-plastic half-space. Non-destructive dynamic indentation method is one of more efficient for mechanical properties assessment because of compact instrument that makes it possible of measuring at any point of structure. The scheme of impact indentation was considered and the problem of elastic-plastic impact is solved. The device with a computer way of information processing was created and tested for determining the characteristics of the existing structures. The method was adopted and tested on bridge structures, butt welded joints, civil engineering structures and others

The non-stationary dynamic of a beam under the elastic-plastic impact of a conical indenter

The problem of impact interaction of a conical indenter with the surface of a steel beam under elastic-plastic deformation is considered. The analysis of the dynamic reaction of the beam to the impact is considered analytically and numerically. The analytical solution is based on the phenomenological model of conical indentation and the solution of wave equations of beam dynamics at impact. The numerical study of the indentation process was carried out using the ANSYS software. The dynamic response of the beam is analyzed for different geometric parameters and different values of strength characteristics. Such tasks are widely used in construction practice in the implementation of non-destructive methods of assessing the mechanical characteristics of structures