scholarly journals Blast Damage Assessment of Symmetrical Box-Shaped Underground Tunnel According to Peak Particle Velocity (PPV) and Single Degree of Freedom (SDOF) Criteria

Symmetry ◽  
2018 ◽  
Vol 10 (5) ◽  
pp. 158 ◽  
Author(s):  
Mohamed Mussa ◽  
Azrul Mutalib ◽  
Roszilah Hamid ◽  
Sudharshan Raman
Keyword(s):  
Particle Velocity ◽  
Damage Assessment ◽  
Degree Of Freedom ◽  
Peak Particle Velocity ◽  
Single Degree Of Freedom ◽  
Underground Tunnel ◽  
Single Degree ◽  
Blast Damage

Single-Degree-of-Freedom Based Pressure-Impulse Diagrams for Blast Damage Assessment

2014 ◽  
Vol 567 ◽  
pp. 499-504 ◽  
Author(s):  
Zubair Imam Syed ◽  
Mohd Shahir Liew ◽  
Muhammad Hasibul Hasan ◽  
Srikanth Venkatesan
Keyword(s):  
Damage Assessment ◽  
Structural Response ◽  
Blast Loading ◽  
Computational Effort ◽  
Degree Of Freedom ◽  
Negative Phase ◽  
Single Degree Of Freedom ◽  
Pressure Impulse ◽  
Single Degree ◽  
Structural Resistance

Pressure-impulse (P-I) diagrams, which relates damage with both impulse and pressure, are widely used in the design and damage assessment of structural elements under blast loading. Among many methods of deriving P-I diagrams, single degree of freedom (SDOF) models are widely used to develop P-I diagrams for damage assessment of structural members exposed to blast loading. The popularity of the SDOF method in structural response calculation in its simplicity and cost-effective approach that requires limited input data and less computational effort. The SDOF model gives reasonably good results if the response mode shape is representative of the real behaviour. Pressure-impulse diagrams based on SDOF models are derived based on idealised structural resistance functions and the effect of few of the parameters related to structural response and blast loading are ignored. Effects of idealisation of resistance function, inclusion of damping and load rise time on P-I diagrams constructed from SDOF models have been investigated in this study. In idealisation of load, the negative phase of the blast pressure pulse is ignored in SDOF analysis. The effect of this simplification has also been explored. Matrix Laboratory (MATLAB) codes were developed for response calculation of the SDOF system and for repeated analyses of the SDOF models to construct the P-I diagrams. Resistance functions were found to have significant effect on the P-I diagrams were observed. Inclusion of negative phase was found to have notable impact of the shape of P-I diagrams in the dynamic zone.

Experimental–theoretical investigation for damage assessment of a reinforced concrete slab under consecutive explosions based on single-degree-of-freedom model

2020 ◽  
pp. 204141962093806
Author(s):  
Seung-Hun Sung ◽  
Hun Ji ◽  
Jinwung Chong
Keyword(s):  
Reinforced Concrete ◽  
Damage Assessment ◽  
Concrete Slab ◽  
Permanent Deformation ◽  
Degree Of Freedom ◽  
Dynamic Responses ◽  
Reinforced Concrete Slab ◽  
Element Analysis ◽  
Single Degree Of Freedom ◽  
Single Degree

This study performed damage assessment of a reinforced concrete slab subjected to consecutive explosions. To this end, the resistance functions were updated to account for the permanent displacement calculated in the previous step to capture the response of the reinforced concrete slab of the current explosion. In other words, the permanent deformation should be basically evaluated according to the prior explosion. Next, the revised resistance function should be calculated according to damage level. Third, the maximum dynamic responses should be estimated based on the modified single-degree-of-freedom model. Finally, cumulative damages can be evaluated based on the sum of the permanent deformation and the maximum dynamic responses. In order to confirm a feasibility of the proposed single-degree-of-freedom model, a comparative study with the finite element analysis results is carried out under the identical consecutive explosions. Prior to performing the comparative study, the computational model of the target structure is calibrated based on small-scale experimental data to carry out more reliable finite element analysis.

Kinematic comparison of single degree-of-freedom robotic gait trainers

2021 ◽  
Vol 159 ◽  
pp. 104258
Author(s):  
Jeonghwan Lee ◽  
Lailu Li ◽  
Sung Yul Shin ◽  
Ashish D. Deshpande ◽  
James Sulzer
Keyword(s):  
Degree Of Freedom ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Robotic Gait
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