Mechanical effects due to pulse width variation of shock inputs. The disk is fixed to a rig which subjects it to a half sine acceleration pulse which lasts for 6ms 0. How does that compare with the frequency of your half sine, which at ms is a 38. The half sine wave impulse was to replace impact response of disk drive. The unit g or g represents multiples of the acceleration of gravity and is conventionally used.
Drop test simulation made easy with ansys simulation. If you are doing sine onrandom mixed mode testing, it is often useful to be able to convert between psd and sine amplitude and vice versa. Prestigious companies in northern california turn to ozen engineering as the singlesource of reliable simulation solutions. Although ozen engineering is headquartered in the heart of silicon valley, we collaborate with bestinclass companies worldwide to optimize product design performance and improve product development processes for our clients wherever they are located and across a wide. Shock and vibration analysis using ansys mechanical normal. A shock pulse can be characterised by its peak acceleration, the duration, and the shape of the shock pulse half sine, triangular, trapezoidal, etc. Im new to ansys fluent, so sorry if this is a basic question. After preprocessing in hypermesh, the model is analyzed using lsdyna, a commercially available finite element transient solver. Allen and bogy 2 studied the shock res ponse at the componen t level for the disk, the su spension and the slider. Apr 17, 2017 analysis for shock absorber in ansys r16 i am.
Ansys have a number of different mode combinations methods. Calculation of shock response spectrum vsb tu of ostrava. Hi all,one of our customers has submitted a spec for operating shock and vibration per milstd 167 with certain values. Vibration analysis of a twostep sine movable tooth drive. Shock analysis on a packaged washing machine from damage. Study of the shock response of the hdd with ansys lsdyna. And evaluation of shock response of a mixed flow fan david jonathan gonzalez campos for many engineers that use finite element analysis or fea, it very important to know how to is. Ansys mechanical workbench supports response spectrum analysis. I will sit down with the engineer in my dept tomorrow, i am a designe.
The purpose of this report is to explain the shock response spectrum and to give a. How can i define a halfsine, a sawtooth, or a rectangular. Fabrication and characterization of a multidirectional. Singlepoint response spectrum a single response spectrum excites all specified points in the model.
Download scientific diagram halfsine wave shock loads with various initial. The acceleration may, for example, be 20 g, 50 g, or 100 g g 9. I have done a quick test using ansys mechanical by applying a global acceleration of 500ms2 to the disk and fixing the outer bosses. Ansys apdl commands objects after response spectrum analysis. Shock response spectrum f n1 shock is recorded in digital form, commonly as acceleration signal. Then the head slap behavior of the slider in the nonoperating state is simulated with the implicittoexplicit analysis function of ansys. Study of the shock response of the hdd with ansyslsdyna. Note that milstd1540c and milstd810e require this format for certain shock environments. Pdf study of the shock response of the hdd with ansyslsdyna. This is a mode superposition method that requires the model to be. If so, share your ppt presentation slides online with. Calculation of shock response spectrum vsb tu of ostrava faculty of mechanical engineering. These equations strictly apply only in the linear region of response.
A flat disc with a central mass is subjected to a shock test. The finite element model fem analysis package, ansys, is used to calculate the natural frequencies and vibration modes of the drive system. The applied half sine shock acceleration with different amplitudes can be obtained by adjusting the predetermined height of the dropping table. For the free online simulation course from cornell university, ansys student 2019 r3 is recommended. A semi sine acceleration pulse is applied to the shaft and the central zone of the disk at the same time. The drop height was increased until 400 mm when one straightened suspender failed. Xansys view topic xansys dynamic amplification factor. Element analysis fea with the ansys software was conducted to obtain the relative displacement of a key point of the motor. I basically want to model a shock tube, where pressurized air is kept behind a diaphragm in an enclosed tube, and at t0 the diaphragm bursts and the pressurized air propagates in the enclosed tube. The acceleration amplitude, as well as the duration of the shock, can have different values. Halfsine shock earth gravity ansys student community.
The shock is simulated as half sine wave acceleration applied at the enclosure base of the hard disk drive. Either singlepoint or multipoint response spectrum analysis can be performed. Shock analysis using the pseudo velocity shock spectrum part 1 is the property of its rightful owner. In this study, a 3d model of a twostep sine movable tooth drive is developed in the ug software. Shock pulse width effects in operational drop test simulation.
A half sine pulse of acceleration was applied to the model by edload command. Depending on the results requested in analysis settings for a response spectrum solution, velocity and acceleration results can be obtained, in addition to deflection, stress and strain. The shock tests were repeated twice at a 400 mm drop height. Ansys spaceclaim modeling and transient structural fea of camshaftrockervalve assembly. The shock profile can be approximated as a half sine, a sawtooth, or a rectangular pulse. Jun 24, 2014 performing shock response spectrum calculation from a acceleration time history signal free download at. Shock analysis of a new ultrasonic motor subjected to halfsine. How to improve the strength of submerged structures for undertaking the underwater explosion loading is an important problem confronted by the designers of surface ships and submarines.
People who resort this problem with lsdyna or ansyslsdyna will be normally directed to the default element technology, which is reduced integration constant stress or ri. The results show that the first twenty natural frequencies can be classified into five families, including the total system vibration mode, singleelement. Conformable hydrogen tanks need for standards development. 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. Ansys spaceclaim modeling and transient structural fea of camshaftrockervalve assembly duration. Since the finite element software cannot directly input the half sine wave load in explicit analysis, total 19 time steps to approximate the half sine curve into 18 intervals were applied for the varied acceleration. A half sine acceleration pulse is applied to pivot shaft and central zone of the disk at the same time. Functional shock test per milstd810 equivalent static load. Xansys view topic xansys struc how to apply damping. Feb 24, 2004 i did a shock analysis in ansyslsdyna version. Shock is a vector that has units of an acceleration rate of change of velocity. A common description of impact, used in several standards, is a half sine acceleration pulse.
The student community is a public forum for authorized ansys academic product users to share ideas and ask questions. Transient structural dynamic shock analysis of compressor base. Halfsine wave shock loads with various initial velocities to the base. If you have a modal analysis and link the solution of the modal into the setup cell of the transient structural, you will be making it a linear analysis, which is good to do for a first evaluation.
Case study for northrop grumman information systems lx course. It depicts ansys workbench transient dynamic shock analysis. The transient dynamic model needs to be linear for this to work well i think, so its usually not that big a deal to run a linear transient analysis with the half sinusoid shock load. Ansys mechanical apdl and mechanical workbench can perform harmonic analysis on a structure, determining the steadystate sinusoidal response to. A half sine acceleration pulse is applied to pivot shaft and central zone of the disk at the. Drop test and finite element analysis of test board. Among the many parameters start programs ansys release 7. Its usually defined as half sine wave, otherwise described differently by companys specification. Comparison of transient vs rsdiff mode combinations results. Shock response spectrum analysis is a fast and easy way to get started with shock and drop simulations. A half sine pulse was provided as an input shock pulse to washing machine with the bottom cushion pad fastened to the shock table. Research on the shock resistance optimal design of small. 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.
Functional shock test per milstd810 equivalent static load mechengdude mechanical op. Timehistory analysis of simple structures under shock. In this paper, a fe model of the st drive is developed in ansys, which includes pivot bearing, hsa and disk. Can the stress analysis perform what i need to simulate. I want to know how to define it in ansys function editor. A correlation was developed between linear and rotary shock tests.
The impact is assumed to be a half sine loading with a hand caclulated time duration expressed a a harmonic frequency. Srs of a half sine impulse half sine impulse 11 ms 0 2 4 6 8 10 12. Resonant frequencies are compared with the modal testing results. Standard image export powerpoint slide figure 11 shows the drop hammer experiment results. Ive used this technique to do half sinusoid shock test simulation on electronics equipment, and gotten good correlation with ansys transient results. Performing shock response spectrum calculation from a acceleration time history signal free download at.
A halfsine acceleration pulse is applied to pivot shaft and central zone of the disk at the same time. Base acceleration in harmonic analysis using ansys mechanical. It is a great choice if your professor is already using it for your course or if you are already familiar with the ansys workbench platform. Sep 23, 2019 the student community is a public forum for authorized ansys academic product users to share ideas and ask questions. A study of shock analysis using the finite element method. A study of shock analysis using the finite element method verified with euler bernoulli beam theory. Ansys student is used by hundreds of thousands of students globally. My model had a cantilever beam, and my model was meshed totally with solid164 elements. Explicit dynamics solution depends only on previous time step requires a very small subs time step limited to problem with duration in milliseconds or less. The shock response spectrum is a useful tool for estimating the damage potential of a shock pulse, as well as for test level specification.
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