scholarly journals Minor Structures for the Improvement of Wave Disturbance in a Small Harbor

2018 ◽  
Vol 2018 ◽  
pp. 1-10
Author(s):  
A. Sulis
Keyword(s):  
Boussinesq Equations ◽  
Wave Disturbance ◽  
Comprehensive Description ◽  
New Energy ◽  
Efficient Alternative ◽  
Operational Activities ◽  
Traditional Structures ◽  
Energy Absorbing ◽  
Incident Waves ◽  
Large Research

A very important aspect in the planning, design, and maintenance of a harbor is to determine the response of the harbor basin to incident waves. The Saras harbor in South Sardinia (Italy) has been experiencing significant wave disturbance that affects the safety of mooring and operational activities. In the framework of a large research, this paper summarises a comprehensive description of new energy absorbing structures that can be seen as an efficient alternative to more traditional structures when limited by economic or technical constraints. Specifically, the paper presents the results of a graphical preliminary approach and a numerical modelling that solves the enhanced Boussinesq equations in two horizontal dimensions.

scholarly journals Investigation of Energy-Absorbing Properties of a Bio-Inspired Structure

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 881
Author(s):  
Adrian Dubicki ◽  
Izabela Zglobicka ◽  
Krzysztof J. Kurzydłowski
Keyword(s):  
Absorption Capacity ◽  
Compression Tests ◽  
Element Analysis ◽  
Lightweight Structures ◽  
New Energy ◽  
Absorbing Material ◽  
Lightweight Structure ◽  
3D Printed ◽  
Deformation Force ◽  
Energy Absorbing

Numerous engineering applications require lightweight structures with excellent absorption capacity. The problem of obtaining such structures may be solved by nature and especially biological structures with such properties. The paper concerns an attempt to develop a new energy-absorbing material using a biomimetic approach. The lightweight structure investigated here is mimicking geometry of diatom shells, which are known to be optimized by nature in terms of the resistance to mechanical loading. The structures mimicking frustule of diatoms, retaining the similarity with the natural shell, were 3D printed and subjected to compression tests. As required, the bio-inspired structure deformed continuously with the increase in deformation force. Finite element analysis (FEA) was carried out to gain insight into the mechanism of damage of the samples mimicking diatoms shells. The experimental results showed a good agreement with the numerical results. The results are discussed in the context of further investigations which need to be conducted as well as possible applications in the energy absorbing structures.

New Energy-Absorbing High-Speed Safety Barrier

2003 ◽  
Vol 1851 (1) ◽  
pp. 53-64 ◽  
Author(s):  
John D. Reid ◽  
Ronald K. Faller ◽  
Jim C. Holloway ◽  
John R. Rohde ◽  
Dean L. Sicking
Keyword(s):  
High Speed ◽  
Steel Tube ◽  
Full Scale ◽  
Element Analysis ◽  
Dynamic Component ◽  
Testing Program ◽  
Roadside Safety ◽  
New Energy ◽  
University Of Nebraska Lincoln ◽  
Energy Absorbing

For many years, containment for errant racing vehicles traveling on oval speedways has been provided through rigid, concrete containment walls placed around the exterior of the track. However, accident experience has shown that serious injuries and fatalities may occur through vehicular impacts into these nondeformable barriers. Because of these injuries, the Indy Racing League and the Indianapolis Motor Speedway, later joined by the National Association for Stock Car Auto Racing (NASCAR), sponsored the development of a new barrier system by the Midwest Roadside Safety Facility at the University of Nebraska–Lincoln to improve the safety of drivers participating in automobile racing events. Several barrier prototypes were investigated and evaluated using both static and dynamic component testing, computer simulation modeling with LS-DYNA (a nonlinear finite element analysis code), and 20 full-scale vehicle crash tests. The full-scale crash testing program included bogie vehicles, small cars, and a full-size sedan, as well as Indy Racing League open-wheeled cars and NASCAR Winston Cup cars. A combination steel tube skin and foam energy-absorbing barrier system, referred to as the SAFER (steel and foam energy reduction) barrier, was successfully developed. Subsequently, the SAFER barrier was installed at the Indianapolis Motor Speedway in advance of the running of the 2002 Indianapolis 500 race. From the results of the laboratory testing program as well as analysis of the accidents into the SAFER barrier occurring during practice, qualification, and the race, the SAFER barrier has been shown to provide improved safety for drivers impacting the outer walls.

Application of a Hybrid Boussinesq-Panel Model for Motion Predictions of a Moored Sevan-Floater in Finite Water Depth

2017 ◽  
Author(s):  
Jikun You ◽  
Einar Bernt Glomnes
Keyword(s):  
Water Depth ◽  
Low Frequency ◽  
Boussinesq Equations ◽  
Wave Force ◽  
Irregular Waves ◽  
Wave Forces ◽  
Rankine Source ◽  
Panel Model ◽  
Finite Water Depth ◽  
Incident Waves

This paper presents the applications of an efficient hybrid time-domain simulation model for predicting moored Sevan-floater motions in irregular waves and finite water depth. The irregular incident waves are modeled by the extended Boussinesq equations, which can capture wave-wave interactions and the low-frequency long waves accurately in finite and shallow water depth. By imposing the incident wave kinematics on the surface of the floater, a panel model based on Rankine source method is applied for the calculation of wave forces and corresponding floater motions. The contributions from low-frequency components in incident waves as well as their diffraction effects are included in the wave force calculations. Validation of the irregular waves simulated by the present numerical model are performed against experimental data. Then, the simulated moored floater motions are compared with model test results and results based on Newman’s approximation. The general good agreements with experimental results demonstrate the present model can be used as an alternative for this problem while Newman’s approximation shows non-conservative results.

The challenges of organizational agility (part 1)

2017 ◽  
Vol 49 (1) ◽  
pp. 6-14 ◽  
Author(s):  
Steven H. Appelbaum ◽  
Rafael Calla ◽  
Dany Desautels ◽  
Lisa Hasan
Keyword(s):  
Competitive Advantage ◽  
Organizational Performance ◽  
High Speed ◽  
Dynamic Capabilities ◽  
Environmental Changes ◽  
Continuous Change ◽  
Organizational Agility ◽  
Content Type ◽  
Operational Activities ◽  
Traditional Structures

Purpose Planned episodic change programs, rigid processes and traditional structures, optimized for efficiency rather than agility, are no longer appropriate in a context where competitive advantage is fueled by high-speed innovation, supported by a more entrepreneurial mindset. The purpose of this two part paper is to offer a review of relevant research to provide an informed case for continuous strategic transformation facilitated by enhanced organizational agility. The concept of agility is explored, defined and a framework for categorizing agility-enhancing capabilities is presented. Specific aspects of this agility framework are examined to better understand how these interrelated competencies contribute to overall corporate performance in this fast-paced world. Design/methodology/approach A range of published empirical and practitioner research articles were reviewed to study the concepts of organizational agility and transformation as critical factors contributing to sustained competitive advantage, organizational performance and survival in the increasingly competitive global context. This literature review explores how organizations are overcoming the challenges imposed by their traditional structures, cultures and leadership models and identifies dynamic competencies to be developed to achieve a greater level of corporate agility. Findings Increased organizational agility increases the ability to respond proactively to unexpected environmental changes. The commitment to continuous transformation and agile strategies implies changes at all levels of the organization from its structure, through its leadership and decision-making dynamics, down to the skills and interpersonal relationships of the individuals implementing the agile mission. Research limitations/implications There is a gap in the literature with respect to agility, namely, that most research focuses on the characteristics of agile organizations, with little attention given to how to develop agile capabilities and embed the commitment to continuous change deep into the corporate DNA, beyond the process level, into the psyche of the people driving the organization. Practical implications Managers should consider agility as an overarching principle guiding strategic and operational activities. Fostering agility-enhancing capabilities will be paramount in ensuring the successful integration of agility as a performance enhancing paradigm. Social implications For small- and medium-sized companies with limited resources, this reality makes staying relevant an uphill battle but also opens windows of opportunity. The challenge of the next century for large organizations will be to rekindle their innovative agile beginnings and for start-ups to continue to foster their dynamic capabilities as they grow. Originality/value The paper provides practical and empirical evidence of the importance of enterprise agility and specific dynamic capabilities on firm performance.

scholarly journals Laboratory Testing on Energy Absorption of High-Damping Rubber in a New Bolt for Preventing Rockburst in Deep Hard Rock Mass

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Lu Chen ◽  
Qingwen Li ◽  
Jianming Yang ◽  
Lan Qiao
Keyword(s):  
Rock Mass ◽  
Energy Absorption ◽  
Hard Rock ◽  
Split Hopkinson Pressure Bar ◽  
Absorption Characteristic ◽  
Hopkinson Pressure Bar ◽  
Mining Depth ◽  
New Energy ◽  
High Damping Rubber ◽  
Energy Absorbing

With the increase in mining depth, the deep hard rock mass is under threat of rockburst under high geostress, high temperature, high osmotic pressure, and strong disturbance. To reduce the probability and strength of rockburst, a new energy-absorbing bolt for guaranteeing the stability of deep hard rock mass was developed utilizing the energy absorption characteristic of high-damping rubber. To analyze the practicability and obtain the quantified behaviors of this new energy-absorbing bolt, a series of impact tests on specimens of high-damping rubber, granite, and granite–rubber composite specimens was carried out by a split Hopkinson pressure bar (SHPB) method. Further, considering the different working depths with different rock temperatures, the dynamic energy-absorbing characteristics of high-damping rubber under different temperatures were tested. The testing results show that the new energy-absorbing bolt can consume the storage energy in host rock effectively, and the environmental temperature will produce certain effects on the energy-consuming rate. In addition, the optimal energy-absorbing thickness–diameter ratio of high-damping rubber was confirmed by SHPB tests.

The challenges of organizational agility: part 2

2017 ◽  
Vol 49 (2) ◽  
pp. 69-74 ◽  
Author(s):  
Steven H. Appelbaum ◽  
Rafael Calla ◽  
Dany Desautels ◽  
Lisa N. Hasan
Keyword(s):  
Competitive Advantage ◽  
Organizational Performance ◽  
High Speed ◽  
Dynamic Capabilities ◽  
Environmental Changes ◽  
Continuous Change ◽  
Organizational Agility ◽  
Content Type ◽  
Operational Activities ◽  
Traditional Structures

Purpose Planned episodic change programs, rigid processes and traditional structures, optimized for efficiency rather than agility, are no longer appropriate in a context where competitive advantage is fueled by high-speed innovation, supported by a more entrepreneurial mindset. The purpose of this paper is to offer a review of relevant research to provide an informed case for continuous strategic transformation facilitated by enhanced organizational agility. The concept of agility is explored, defined and a framework for categorizing agility-enhancing capabilities is presented. Specific aspects of this agility framework are examined to better understand how these interrelated competencies contribute to overall corporate performance in this fast-paced world. Design/methodology/approach A range of published empirical and practitioner research articles were reviewed to study the concepts of organizational agility and transformation as critical factors contributing to sustained competitive advantage, organizational performance and survival in the increasingly competitive global context. This literature review explores how organizations are overcoming the challenges imposed by their traditional structures, cultures and leadership models and identifies dynamic competencies to be developed to achieve a greater level of corporate agility. Findings Increased organizational agility increases the ability to respond proactively to unexpected environmental changes. The commitment to continuous transformation and agile strategies implies changes at all levels of the organization from its structure, through its leadership and decision-making dynamics, down to the skills and interpersonal relationships of the individuals implementing the agile mission. Research limitations/implications There is a gap in the literature with respect to agility, namely that most research focuses on the characteristics of agile organizations, with little attention given to how to develop agile capabilities and embed the commitment to continuous change deep into the corporate DNA, beyond the process level, into the psyche of the people driving the organization. Practical implications Managers should consider agility as an overarching principle guiding strategic and operational activities. Fostering agility-enhancing capabilities will be paramount in ensuring the successful integration of agility as a performance enhancing paradigm. Social implications For small- and medium-sized companies with limited resources, this reality makes staying relevant an uphill battle but also opens windows of opportunity. The challenge of the next century for large organizations will be to rekindle their innovative agile beginnings and for start-ups to continue to foster their dynamic capabilities as they grow. Originality/value The paper provides practical and empirical evidence of the importance of enterprise agility and specific dynamic capabilities on firm performance.

Improved Crashworthy Aircraft Seat Design

2002 ◽  
Author(s):  
Kash Kasturi ◽  
Peter Kwok
Keyword(s):  
Energy Absorption ◽  
Integrated Design ◽  
Model Verification ◽  
Structural Members ◽  
Additional Energy ◽  
Precise Control ◽  
Occupant Protection ◽  
Passenger Seat ◽  
New Energy ◽  
Energy Absorbing

An innovative transport aircraft passenger seat concept for superior occupant protection, meeting all structural requirements used in typical seat designs was developed. This was accomplished with the use of new energy-absorbing structural members and precise control of seat deformation characteristics. Advanced dynamic finite element modeling technique was utilized to analyze the integrated design of the seat, occupants, restraints and energy absorbing elements. Results from certification tests on an existing seat design were used to validate the analytical model. Verification studies have shown good correlation between the analytical simulations and the test data. In addition, further improvements to occupant protection of this new aircraft seat design were accomplished by incorporating the seat back tilt mechanism coupled with the use of shoulder belt. The seat back tilt mechanism utilizes similar energy-absorption concept and provides additional energy absorption while being pulled forward by the shoulder belt.

scholarly journals A New Energy-Absorbing Device for Motion Suppression in Deep-Sea Floating Platforms

Energies ◽  
2014 ◽  
Vol 8 (1) ◽  
pp. 111-132 ◽  
Author(s):  
Xiaohui Zeng ◽  
Yang Yu ◽  
Liang Zhang ◽  
Qingquan Liu ◽  
Han Wu
Keyword(s):  
Deep Sea ◽  
New Energy ◽  
Energy Absorbing ◽  
Floating Platforms ◽  
Motion Suppression
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