Introduction
In the field of environmental reliability testing and structural dynamics research, shakers are key equipment to simulate the vibration environment of products during transportation and use. Electric shaker and hydraulic shaker table are two mainstream technical solutions, and their working principles, performance characteristics and application scenarios are significantly different. This article aims to systematically compare the technical performance of the two and provide an objective selection guide based on common domestic and international standards (such as IEC 60068-2 series, ASTM D4728, etc.) and engineering practices to assist engineers and researchers in making appropriate choices according to specific needs.
How it works:
The motorized shaker works on the principle of electromagnetic induction. Its core is the moving coil in a strong magnetic field, when the alternating current passes through the moving coil, it produces reciprocating motion under the action of electromagnetic force, thereby driving the vibration of the countertop. Its system is mainly composed of a power amplifier, a shaker body (including a moving coil and an excitation device) and a control system.
The hydraulic shaker table is based on the hydraulic servo principle. Under the control of the servo valve, the hydraulic oil pushes the piston in the actuator cylinder to produce linear motion, which then drives the table. Its system mainly includes hydraulic power source (oil pump, oil tank), servo valve, actuator cylinder, accumulator and controller.
Comparison of performance parameters
The following table compares the key performance indicators of the two types of shakers from multiple dimensions, which directly determine their scope of application.
| Compare projects | Motorized shaker | Hydraulic shaker |
| Frequency range | They are usually wider and can range from a few Hz to thousands of Hz | Usually lower, from DC or near 0Hz to hundreds of Hz |
| Thrust/load capacity | Medium to high thrust, limited by the heat dissipation of the moving coil | Maximum thrust and load capacity can be achieved |
| Maximum displacement | Relatively small, usually tens of millimeters | Very large, up to hundreds of millimeters or even larger |
| Acceleration waveform mass | In the high frequency band, waveform distortion is usually low | It performs well at low frequencies with large displacements, and high frequencies are limited |
| Running costs | It mainly consumes electrical energy and is relatively simple to maintain on a daily basis | It consumes electrical energy and hydraulic oil, and requires regular maintenance of the hydraulic system |
| Typical installation | Usually no special foundation is required, and the installation environment requirements are relatively flexible | The foundation needs to be strong to withstand huge static loads and reaction forces |
Selection considerations
Choosing a shaker type is not a simple comparison of parameters, but a comprehensive trade-off based on specific testing needs, standards, and budget.
1. Test standards and frequency requirements
If the test standard requires coverage of wide-band random vibration or high-frequency resonant searches (e.g., > 500 Hz), motorized shakers are usually the more suitable choice. Its frequency is capped at FmaxIt is related to the stiffness of the system and the quality of the moving parts, which can be approximately determined by the resonant frequency of the system. For tests that require simulating extremely low frequencies (<1 Hz) or DC displacements (e.g., seismic wave simulation), hydraulic shakers have a natural advantage.
2. Specimen characteristics and mechanical requirements
The mass of the specimen M, the maximum acceleration A and the maximum displacement D required for testing are the core calculation parameters. The required thrust F can be preliminarily estimated as: F = M × A. For large masses (e.g. more than a few tons) or specimens that require large displacements, hydraulic shakers tend to be more cost-effective. At the same time, it is necessary to consider the matching of the size of the specimen and the size of the table to avoid lateral movement or table deformation caused by improper installation.
3. Waveform control and accuracy requirements
Due to its fast response speed, motorized shakers generally perform better in achieving high-precision sine sweep, stochastic vibration control, and transient waveform reproduction. Due to the compressibility of the oil and the pipeline dynamics, the phase and control accuracy of the hydraulic system in the high frequency band will face challenges, but the thrust smoothness is better under the large displacement of the low frequency.
4. Facilities and life cycle costs
Hydraulic shakers require a dedicated hydraulic oil source, cooling system and a solid foundation, with high initial investment and installation complexity, as well as maintenance costs such as hydraulic oil leakage and regular replacement. Electric shakers are relatively easy to install, but high-thrust equipment also requires high-capacity power supply and cooling systems. The total cost of ownership takes into account equipment acquisition, installation, energy consumption, and long-term maintenance costs.
Typical application scenario guidance
Scenarios that prioritize electric shakers:reliability screening and vibration function testing of electronic products, components, aerospace airborne equipment, and auto parts; Tests of high-frequency vibration, high-acceleration random vibration, or precise sinusoidal resonance residency are required; Occasions where laboratory space is limited or large foundations cannot be built.
Scenarios that prioritize hydraulic shakers:seismic simulation tests of large structural parts (such as vehicles, building components), heavy equipment, wind turbine towers, and bridge models; fatigue testing that requires extreme displacement or static load superimposed on dynamic load; Testing to reproduce long-period time-domain waveforms (e.g., transport vibration recordings) at low speeds.
Conclusion
Electric shakers and hydraulic shakers have their own technical advantages and applicable areas, and there is no universal solution. Selection decisions should begin with a clear definition of test criteria, specimen parameters, and test objectives. It is recommended to set up a selection team covering test engineers and equipment engineers, and if necessary, detailed test specifications can be provided to equipment suppliers to obtain customized technical solutions and performance commitments. Choosing a platform that can reliably meet current and foreseeable future needs within budget, taking into account installation conditions and operating costs, is key to achieving efficient and reliable vibration testing.
References
1. IEC 60068-2-6, Environmental testing - Part 2-6: Tests - Test Fc: Vibration (sinusoidal).
2. ASTM D4728, Standard Test Method for Random Vibration Testing of Shipping Containers.
3. Harris, C. M., & Piersol, A. G., Shock and Vibration Handbook, related chapters.
4. Relevant parts of the domestic mechanical vibration and shock standard system (GB/T 2423 series).