Catalogue Search | MBRL
Are you sure you want to remove the book from the shelf?
{{itemTitle}}
3,592
result(s) for
"Shock (Mechanics)"
Sort by:
Mechanical Vibration and Shock Analysis, Specification Development
Everything engineers need to know about mechanical vibration and shock...in one authoritative reference work! This fully updated and revised 3rd edition addresses the entire field of mechanical vibration and shock as one of the most important types of load and stress applied to structures, machines and components in the real world. Examples include everything from the regular and predictable loads applied to turbines, motors or helicopters by the spinning of their constituent parts to the ability of buildings to withstand damage from wind loads or explosions, and the need for cars to maintain structural integrity in the event of a crash. There are detailed examinations of underlying theory, models developed for specific applications, performance of materials under test conditions and in real-world settings, and case studies and discussions of how the relationships between these affect design for actual products. Invaluable to engineers specializing in mechanical, aeronautical, civil, electrical and transportation engineering, this reference work, in five volumes is a crucial resource for the solution of shock and vibration problems. This volume focuses on specification development in accordance with the principle of tailoring. Extreme response and the fatigue damage spectra are defined for each type of stress (sinusoidal vibration, swept sine, shock, random vibration, etc.). The process for establishing a specification from the life cycle profile of equipment which will be subject to these types of stresses is then detailed. The analysis takes into account the uncertainty factor, designed to cover uncertainties related to the real-world environment and mechanical strength, and the test factor, which takes account of the number of tests performed to demonstrate the resistance of the equipment.
eBook
Formulas for Mechanical and Structural Shock and Impact
In dealing with extreme loads on structures, simple approximations of key variables can indicate if there is a threat of collapse. The ability to determine such variables early on strongly impacts the decisions about the engineering approach to adopt. This book is a self-contained and concise presentation of formulas and methodology you can use to determine dynamic response to shock loads, to help you decide on the optimal design. This book offers insight into how objects and structures respond to sudden, strong-and generally short-impulses. In our computer-oriented environment, in which structural programs are used for most large analytical tasks, engineers can still benefit from certain manual calculations and analytical methods to quickly assess the situation at hand. Exploring a range of mechanical and civil engineering applications, the text enables engineers to manually calculate what happens to structures and objects when pushed, pulled, jerked, or blasted by providing ready access to formulas required for advanced problem solving.
eBook
Impact of shock index
Heart failure (HF) is still associated with quite considerable mortality rates and usage of simple tools for prognosis is pivotal. We aimed to evaluate the effect of shock index (SI) and its derivatives (age SI (ASI), modified SI (MSI), and age MSI (AMSI)) on acute HF (AHF) clinical outcomes. PubMed/Medline, Scopus and Web of science databases were screened with no time and language limitations till February 2024. We recruited relevant records assessed SI, ASI, MSI or AMSI with AHF clinical outcomes. Eight records were selected (age: 69.44±15.05 years). Mean SI in those records reported mortality (either in-hospital or long-term death) was 0.67 (95% confidence interval (CI):0.63-0.72)). In-hospital and follow-up mortality rates in seven(n = 12955) and three(n = 5253) enrolled records were 6.18% and 10.14% with mean SI of 0.68(95%CI:0.63-0.73) and 0.72(95%CI:0.62-0.81), respectively. Deceased versus survived patients had higher SI difference (0.30, 95%CI:0.06-0.53, P = 0.012). Increased SI was associated with higher chances of in-hospital death (odds ratio (OR): 1.93, 95%CI:1.30-2.85, P = 0.001).The optimal SI cut-off point was found to be 0.79 (sensitivity: 57.6%, specificity: 62.1%). In-hospital mortality based on ASI was 6.12% (mean ASI: 47.49, 95%CI: 44.73-50.25) and significant difference was found between death and alive subgroups (0.48, 95%CI:0.39-0.57, P<0.001). Also, ASI was found to be independent in-hospital mortality predictor (OR: 2.54, 95%CI:2.04-3.16, P<0.001)). The optimal ASI cut-off point was found to be 49.6 (sensitivity: 66.3%, specificity: 58.6%). In terms of MSI (mean: 0.93, 95%CI:0.88-0.98)), significant difference was found specified by death/survival status (0.34, 95%CI:0.05-0.63, P = 0.021). AMSI data synthesis was not possible due to presence of a single record. SI, ASI, and MSI are practical available tools for AHF prognosis assessment in clinical settings to prioritize high risk patients.
Journal Article
Structures under shock and impact XIII
SUSI XIII contains the proceedings of the 13th International Conference in the successful series of Structures under Shock and Impact. Since the first meeting in Cambridge, Massachusetts (1989) the conference has brought together the research works of scientists and engineers from a wide range of academic disciplines and industrial backgrounds that have an interest in the structural impact response of structures and materials. The shock and impact behaviour of structures is a challenging area, not only because of the obvious time-dependent aspects, but also due to the difficulties in specifying the external dynamic loadings, boundary conditions and connection characteristics for structural design and hazard assessment, and in obtaining the dynamic properties of materials. Thus, it is important to recognise and utilise fully the contributions and understand the emerging theoretical, numerical and experimental studies on structures, as well as investigations into the material properties under dynamic loading conditions. Any increased knowledge will enhance our understanding of these problems and thorough forensic studies on the structural damage after accidents will lead to improved design requirements. The range of topics in this very active field is ever expanding. The following list of topics gives an idea of the wide number of applications covered: Impact and Blast Loading; Response of Buildings to Blast; Computational and Experimental Results; Dynamic Analysis of Composite Structures; Energy Absorbtion; Seismic Behaviour.
eBook
Materials and structures under shock and impact
In risk studies, engineers often have to consider the consequences of an accident leading to a shock on a construction. This can concern the impact of a ground vehicle or aircraft, or the effects of an explosion on an industrial site. This book presents a didactic approach starting with the theoretical elements of the mechanics of materials and structures, in order to develop their applications in the cases of shocks and impacts. The latter are studied on a local scale at first. They lead to stresses and strains in the form of waves propagating through the material, this movement then extending to the whole of the structure. The first part of the book is devoted to the study of solid dynamics where nonlinear behaviors come into play. The second part covers structural dynamics and the evaluation of the transient response introduced at the global scale of a construction. Practical methods, simplified methods and methods that are in current use by engineers are also proposed throughout the book. The aim of this book is to present theoretical elements regarding solids and structures, as well as modeling tools in order to study the vulnerability of a structure to a short duration action, generally of accidental nature. The book takes the point of view of an engineer seeking for the modeling of the physics at stake to relevantly carry out his study. The book originality is that it gathers elements from various fields of engineering sciences, for the purpose of a practical objective.
eBook
Hypersonic Shock Wave Turbulent Boundary Layers
This book provides a comprehensive exposition of hypersonic turbulent boundary layers including the fundamental mathematical theory, structure of equilibrium boundary layers, and extensive surveys of Direct Numerical Simulation (DNS), Large Eddy Simulation (LES) and experiments.
eBook
Fractional Calculus with Applications in Mechanics
The books Fractional Calculus with Applications in Mechanics: Vibrations and Diffusion Processes and Fractional Calculus with Applications in Mechanics: Wave Propagation, Impact and Variational Principles contain various applications of fractional calculus to the fields of classical mechanics. Namely, the books study problems in fields such as viscoelasticity of fractional order, lateral vibrations of a rod of fractional order type, lateral vibrations of a rod positioned on fractional order viscoelastic foundations, diffusion-wave phenomena, heat conduction, wave propagation, forced oscillations of a body attached to a rod, impact and variational principles of a Hamiltonian type. The books will be useful for graduate students in mechanics and applied mathematics, as well as for researchers in these fields.Part 1 of this book presents an introduction to fractional calculus. Chapter 1 briefly gives definitions and notions that are needed later in the book and Chapter 2 presents definitions and some of the properties of fractional integrals and derivatives.Part 2 is the central part of the book. Chapter 3 presents the analysis of waves in fractional viscoelastic materials in infinite and finite spatial domains. In Chapter 4, the problem of oscillations of a translatory moving rigid body, attached to a heavy, or light viscoelastic rod of fractional order type, is studied in detail. In Chapter 5, the authors analyze a specific engineering problem of the impact of a viscoelastic rod against a rigid wall. Finally, in Chapter 6, some results for the optimization of a functional containing fractional derivatives of constant and variable order are presented.
eBook
Impact of shock index (SI), modified SI, and age-derivative indices on acute heart failure prognosis; A systematic review and meta-analysis
Heart failure (HF) is still associated with quite considerable mortality rates and usage of simple tools for prognosis is pivotal. We aimed to evaluate the effect of shock index (SI) and its derivatives (age SI (ASI), modified SI (MSI), and age MSI (AMSI)) on acute HF (AHF) clinical outcomes.
PubMed/Medline, Scopus and Web of science databases were screened with no time and language limitations till February 2024. We recruited relevant records assessed SI, ASI, MSI or AMSI with AHF clinical outcomes.
Eight records were selected (age: 69.44±15.05 years). Mean SI in those records reported mortality (either in-hospital or long-term death) was 0.67 (95% confidence interval (CI):0.63-0.72)). In-hospital and follow-up mortality rates in seven(n = 12955) and three(n = 5253) enrolled records were 6.18% and 10.14% with mean SI of 0.68(95%CI:0.63-0.73) and 0.72(95%CI:0.62-0.81), respectively. Deceased versus survived patients had higher SI difference (0.30, 95%CI:0.06-0.53, P = 0.012). Increased SI was associated with higher chances of in-hospital death (odds ratio (OR): 1.93, 95%CI:1.30-2.85, P = 0.001).The optimal SI cut-off point was found to be 0.79 (sensitivity: 57.6%, specificity: 62.1%). In-hospital mortality based on ASI was 6.12% (mean ASI: 47.49, 95%CI: 44.73-50.25) and significant difference was found between death and alive subgroups (0.48, 95%CI:0.39-0.57, P<0.001). Also, ASI was found to be independent in-hospital mortality predictor (OR: 2.54, 95%CI:2.04-3.16, P<0.001)). The optimal ASI cut-off point was found to be 49.6 (sensitivity: 66.3%, specificity: 58.6%). In terms of MSI (mean: 0.93, 95%CI:0.88-0.98)), significant difference was found specified by death/survival status (0.34, 95%CI:0.05-0.63, P = 0.021). AMSI data synthesis was not possible due to presence of a single record.
SI, ASI, and MSI are practical available tools for AHF prognosis assessment in clinical settings to prioritize high risk patients.
Journal Article
A Method for Applying the Use of a Smart 4 Controller for the Assessment of Drill String Bottom-Part Vibrations and Shock Loads
Optimization of drilling processes for oil and gas and geothermal wells requires the effective use of mechanical energy for the destruction of rocks. When constructing a well, an important indicator of the drilling stage is the mechanical speed. Therefore, when performing drilling operations, operators usually use blade bits of an aggressive design and often use forced drilling modes. Drill bits under forced operation modes generate a wide range of vibrations in the drilling tools; in turn, a drill string, being a long-dimensional deformable body, causes the development, amplification, and interconnection of vibrations of different types. Vibration loads reduce the technical and economic indicators of drilling, with destructive effects on drill string elements, and cause complications and emergencies. The authors initiated the creation of an informational and analytical database on emergency situations that occurred as a result of excessive vibrations of the drill string during the construction of deep wells in the deposits of the Dnipro–Donetsk Basin. For the first time, the suitability and effectiveness of using the Smart 4 controller (“Innova Power Solutions”, Calgary, Canada) for monitoring the vibration load of the drilling tool was tested in industrial conditions, while the controller was used as a separate element in the drill string. A special module was developed for the reliable installation of the Smart 4 controller, with a power battery in the layout of the lower part of the drill string. During the testing of the proposed device for measuring vibrations in the process of drilling an inclined well, verification of the registered data was carried out with the help of a high-cost telemetry system. The implementation of the proposed innovation will allow each operator to assess the significance of the impact of vibrations and shocks on the production process and, if necessary, adjust the drilling modes or apply vibration protection devices. In addition, service departments that operate and repair drilling equipment will be able to obtain an evidence base for resolving warranty disputes or claims.
Journal Article