Response of Armour Plate Subjected to Blast Loading Based on Analytical Model of Second Order Single Degree of Freedom

2015 ◽  
Vol 819 ◽  
pp. 387-392
Author(s):  
Ahmad Zaidi Ahmad Mujahid ◽  
Shah Koslan Md Fuad ◽  
Othman Mohd Zaid
Keyword(s):  
Numerical Simulation ◽  
Blast Loading ◽  
Computer Code ◽  
Small Error ◽  
Second Order ◽  
Degree Of Freedom ◽  
Analytical Prediction ◽  
Reliable Technique ◽  
Single Degree Of Freedom ◽  
Single Degree

The rolled homogeneous armour (RHA) plate is commonly used for armoured vehicle skin. Preliminary predictions of the deflections from RHA plate subjected to blast loading is important for establishing guidelines before it is used in vehicle skin. The goal of this work is a reliable technique for predicting the RHA plate response subjected to blast loading, and the empirical result performed by other researchers will be taken as a reference. Based on selected references, a small number of assumptions lead to the developed Single Degree of Freedom (SDOF) idealised models. This paper provides an analytical prediction for the RHA plate response using SDOF in one dimension (1D) approach. The analytical capability was subsequently verified using the non-linear fluid structure interaction (FSI) numerical simulation and the AUTODYN computer code. The midpoint deflections of the RHA plate were taken as the figure of merit. Based on the small error percentage and the support of strong analytical arguments, the second order SDOF analytical approach and numerical simulation using the AUTODYN computer code can be employed as a method of analysis.

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.

An Experimental Hand/Arm Model for Human Interaction With a Telemanipulation System

2001 ◽  
Author(s):  
John E. Speich ◽  
Liang Shao ◽  
Michael Goldfarb
Keyword(s):  
Experimental Data ◽  
Second Order ◽  
Degree Of Freedom ◽  
Human Interaction ◽  
Haptic Interfaces ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Lumped Parameter ◽  
Mass Spring ◽  
System 1

Abstract This paper describes the development of a linear single degree-of-freedom lumped-parameter hand/arm model for the operator of a telemanipulaton system. The model form and parameters were determined from experimental data taken from a single degree-of-freedom telemanipulation system. Typically, the human is modeled as a second order mass-spring-damper system [1, 2]. The model developed in this paper, however, includes an additional spring and damper to better approximate the dynamics of the human while interacting with the manipulator. This model can be used in the design and simulation of control architectures for telemanipulation systems and haptic interfaces.

The Random Response of a Single Degree of Freedom Generalized Maxwell Damping Structure

2015 ◽  
Vol 744-746 ◽  
pp. 1648-1653
Author(s):  
Wan Jie Zou ◽  
Chuan Gao Li ◽  
Yun Xia Zhang
Keyword(s):  
Laplace Transform ◽  
Structural Response ◽  
Second Order ◽  
Degree Of Freedom ◽  
Inverse Laplace Transform ◽  
Maximum Response ◽  
Random Response ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Response Variance

Using the model of stationary white noise excitation, defining the exact analytic method of random response and nearer value of earthquake action about single degree of freedom generalized Maxwell damping, firstly transform the motion equation into standard form, with the Laplace transform and Inverse Laplace transform method, obtained the exact analytical formula of structural response, calculate the response variance by the complex modal method and frequency domain decomposition and make comparisons, The response variance decomposition for the first standard vibrator and second order of the standard vibrator, According to the corresponding relationship between maximum response of the second order vibrator and The design response spectrum, calculated the maximum response by it, base on the maximum response proportion of the first standard vibrator and second, obtained the design of the structural response values and its corresponding earthquake force.

Analytical Prediction of Chatter Stability in Milling—Part II: Application of the General Formulation to Common Milling Systems

1998 ◽  
Vol 120 (1) ◽  
pp. 31-36 ◽  
Author(s):  
E. Budak ◽  
Y. Altintas¸
Keyword(s):  
Numerical Solutions ◽  
Degree Of Freedom ◽  
Analytical Prediction ◽  
Chatter Stability ◽  
Peripheral Milling ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Chatter Prediction ◽  
Milling Chatter ◽  
Two Degree Of Freedom

The general formulation for the milling chatter prediction developed in Part I of the paper is applied to common milling systems. Three cases are considered: a workpiece with single-degree-of-freedom, a face milling cutter with two-degree-of-freedom, and peripheral milling of a cantilevered thin web. The general milling stability formulation is further simplified for the less complicated models. For each case, an analytical expression which explicitly relate the chatter limit to the milling conditions and tool-workpiece dynamics are derived. The analytical predictions are compared with numerical and time domain solutions proposed by previous research. It is shown that the proposed method can accurately predict the chatter limits in milling and thus eliminates the time consuming numerical solutions.

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