The software system receives the acceleration data from a lower computer, then processes the data and uses fft and shock response spectrum srs to judge shock test result. Fft spectrum analyzer and frequency analyzer dewesoft. The naval shock design spectrum including the spectrum dip phenomenon. Response spectrum analysis software caterpillarssa v. Shockresponse spectrum analysis of a bracket inventor. Before the shock response spectrum calculations themselves, these individual shock events can be corrected for dc offset and drift. Find out how your company can benefit from plm built on salesforce. This program calculates the shock response spectrum for a base input, where the base input is in the form of an acceleration time history. The shock response spectrum is a useful tool for estimating the damage potential of a shock pulse, as well as for test level specification. A shock response spectrum srs is a graphical representation of a shock, or any other transient acceleration input, in terms of how a single degree of freedom sdof system like a mass on a spring would respond to that input. This tutorial illustrates response spectrum analysis using a shell model. Dewesoft fft spectrum analyser provides all main functions for spectral analysis with advanced averaging, selectable resolution 64.
Before addressing the details of the shock response spectrum, a few definitions and examples may be helpful. Shock spectrum analysis and response spectrum analysis are methods used to estimate maximum dynamic response of a structure. Response spectrum analysis shock and seismic in femap. Since the exact time history of the load is not known, it is difficult to perform a timedependent analysis. Its origin probably dates from civil engineering and the problem of seismic excitations, i. The shock response spectrum is particularly suited for analyzing pyrotechnic shock. It was adopted by the military after biotmit utilized srs algorithms to develop qualification tests for navy equipment. The analysis moves from the frequency domain to the time domain. Removes the dc component of the calculated time signal. Srs package adds shock response spectrum srs plots to shock and transient capture test modes. Pyroshock testing simulates the high g, high frequency shock environment associated with pyrotechnic events, such as rocket stage separations. Whether using the standard signalcalc dynamic signal analyzer software or the dedicated signalcalc drop test software, the optional srs analysis feature enables shock response spectrum analysis on all input channels. Note that milstd1540c and milstd810e require this format for certain shock environments.
They cover nonlinear, direct transient response, modal frequency response, shockresponse spectrum, and explicit dynamics analyses. Calculate the noise floor of the input time signal. Shock response spectrum is an accepted tool for developing laboratory shock tests. How to perform structural analyses using shock response. Fft spectrum analyzer overview performance and flexibility. It can be used individually or in conjunction with other applications as part of tailored workflows. The fundamental idea behind response spectrum analysis. A response spectrum is simply a plot of the peak or steadystate response of a series of oscillators of varying natural frequency, that are forced into motion by the same base vibration or shock. Introduction shock response spectrum srs analysis was developed as a standard data processing method in the early 1960s. Mathworks is the leading developer of mathematical computing software. Shock response analysis and shock response synthesis.
Using response spectrum analysis can significantly reduce the solution time compared to a full modal time history type of analysis. The units used in this analysis are inches, pounds and seconds inlbs. Define the calculation range for the frequency spectrum. These tutorials provide you with detailed, stepbystep instructions for a variety of different tasks. Response spectrum analysis sol 103 input response spectra created in step 1 plot maximum. Application for calculating the shock response spectrum in order to determine how shocks will affect a structure. There are an infinite number of time signals that have the same shock response spectrum. A response spectrum analysis is based on a superposition of eigenmodes, and it assumes that the response of the structure is predominantly linear. Various shock signal parameters including pulse width, wave shape, peak or faired acceleration and filtering were compared against each other for. The purpose of this report is to explain the shock response spectrum and to give a. Shock response spectrum and shock response synthesis use the same acronym srs.
With the help of ghis shock response spectrum software, several shock signals were created and evaluated against each other in the frequency domain. Response spectrum analysis is a method to estimate the structural response to short, nondeterministic, transient dynamic events. The spectrum can be used in the subsequent response spectrum analysis, or it can be written to a file for future use. Understanding the use and applications of shock response. Response spectrum analysis massachusetts institute of. Transient recorders, shock, vibration data acquisition.
Webinar 16 vibration response spectrum vrs youtube. These are sometimes called srs shock tests, as they are specified with a shock response spectrum srs profile. The dynamic design analysis method ddam is a us navydeveloped analytical procedure for evaluating the design of equipment subject to dynamic loading caused by underwater explosions undex. A study in the application of shock response, spectrum. Sigview spectrum analyzer fft based signal analysis software. Shock response spectrum srs vibration control software. Response spectrum analysis is widely used for the design and assessment of structures that are subject to earthquakes or shock events. Singlepoint response spectrum a single response spectrum excites all specified points in the model. Shock response spectrum using ansys workbench ansys. The srs technique is a straightforward way to characterize a shock environment. Shock response spectrum analysis a shock response spectrum srs is a graphical presentation of a transient acceleration pulses potential to damage a structure. It may also be used for evaluating classical pulses, such as a halfsine pulse. Specialized softwarehardware based on pcs and laptop computers, tabletop shock machines used to test small components.
Drop and shock acquisition shock and drop testing drop. Srs analysis srs package adds shock response spectrum srs plots to shock and transient capture test modes. Supports many generation techniques including linear and exponential chirp, wavesyn, burst random, linear and exponential chirp on burst random, enveloped random, burst sine, or iterate from user waveform. Simacademy shock spectrum analysis msc nastran video. For each damping value the magnitude of the response spectrum must be given over the entire range of frequencies needed, in ascending value of frequency. Nuclear power plant buildings and components, for seismic loading airborne electronic equipment for shock loading commercial buildings in earthquake zones types of response spectrum analysis. Sigview is a realtime and offline signal analysis software package with a wide range of powerful signal analysis tools, statistics functions and a comprehensive visualization system. Harmonic analysis and cepstral analysis advanced parametric sinusoidal modeling is offered. The input to a shock response analysis is a response spectrum, which contains an amplitude as function of the frequency. It plots the peak acceleration responses of a bank of single degreeoffreedom sdof spring, mass damper systems all experiencing the same baseexcitation as if on a rigid massless. The analysis uses a form of shock spectrum analysis that estimates the dynamic response of a component to shock loading caused by the sudden movement of a naval vessel. The analysis finds a solution that fits within the limits of the shaker profile.
The monograph principles and techniques of shock data analysis written by kelly and richman in 1969 has become a seminal reference on the shock response spectrum srs 1. Goal of this analysis is to determine the maximum displacement of the shell body fixed at the corners of the rectangular plate. Examples of such events are earthquakes and shocks. Because of its clear physical descriptions and mathematical presentation of the srs, it has been cited in multiple handbooks on. The advantage of these methods over a conventional transient analysis is economy and simplicity. Input to a response spectrum analysis is the response spectrum, which is defined as the peak response of a single degree of freedom oscillator plotted versus its natural frequency.
Shock response spectrum 0,1 1,0 10,0 100,0 1 10 100 frequency hz g 0 5 10 15 20 absg 0,00 0,02 0,04 0,06 0,08 0,10 0,12 0 6 12 18 24 time s index of the sdof natural frequency input impulse absolute value of sdofsystem responses shock response spectrum peak values peak values as a. In this white paper, learn how you can configure freely without requiring any custom development, and quickly update configurations as your needs evolve. Introduction shock response spectrum srs analysis was developed as a. Multiple channels can be displayed and analyzed in one fft analyzer instrument for easy comparison. The horizontal axis shows the natural frequency of a hypothetical sdof, and the vertical axis shows the peak acceleration which this sdof would undergo as a consequence. The software includes preprocessing of the shock event.
The input data can be viewed before individual shock events are selected for analysis. Pyroshock analysis involves the capture of high frequency transient data performing srs testing and srs analysis. On the shockresponsespectrum recursive algorithm of. How a shock response spectrum can be used in the analysis of linear multidof degree of freedom systems. It also supports defining a test with enveloped data from. Shock response spectrum file exchange matlab central. Shock response spectrum srs analysis is, by definition, the maximum response of a series of single degree of freedom sdof systems of same damping to a given transient signal. Sigview is highly customizable and flexible but does not require any programming knowhow. Shock response spectrum srs analysis and calculations. The reason we want to use a response spectrum is that it allows us to analyze transient events time based events without having.
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