arrow_back_ios

Main Menu

See All 분석 및 시뮬레이션 소프트웨어 See All DAQ 소프트웨어 See All 드라이버 및 API See All 유틸리티 See All 진동 제어 See All 고정밀 및 보정 시스템 See All DAQ 시스템 See All S&V 핸드헬드 장치 See All 산업용 전자 제품 See All 전력 분석기 See All S&V 시그널 컨디셔너 See All 음향 트랜스듀서 See All 전류 및 전압 센서 See All 변위 센서 See All 힘 센서 See All 로드셀 See All 멀티 컴포넌트 센서 See All 압력 센서 See All 스트레인 센서 See All 스트레인 게이지 See All 온도 센서 See All 기울기 센서 See All 토크 센서 See All 진동 트랜스듀서 See All 진동 테스트 장비용 액세서리 See All 진동 컨트롤러 See All 측정 여기기 See All 모달 익사이터 See All 파워 앰프 See All LDS 셰이커 시스템 See All 테스트 솔루션 See All 액추에이터 See All 내연 엔진 See All 내구성 See All eDrive See All 생산 테스트 센서 See All 변속기 및 기어박스 See All 터보 충전기

피로 수명 예측 및 테스트-CAE 상관관계

Three virtual vibration fatigue scenarios you should know about

Vibrations on a physical part can be a source of fatigue.  These vibrations are described in the frequency domain and are usually represented as random power spectral densities (PSDs), harmonics (sine tones and sweeps), or some combination of the two.  In the real world, these vibrations can come from multiple directions (e.g., X, Y, and Z) at the same time.

Electrodynamic shaker tables are commonly used to replicate the vibration environment in a test scenario.  However, tests conducted on an electrodynamic shaker are often limited to a single axis of excitation.

The test can be run as a duty cycle to address this limitation. With this approach, the physical part is repositioned each event in the duty cycle to expose the part to vibrations in each direction.  However, each direction is run independently and sequentially.  Thus, any interaction between the different directions is not captured.

Fortunately, nCode DesignLife can perform virtual vibration fatigue analysis in all the scenarios described below. 

1. Single-axis, random excitation

 

The simplest vibration fatigue analysis within DesignLife uses a single-axis random PSD to describe the loading.  In addition to the PSD loading, the analysis requires a frequency response function (FRF) from finite element analysis (FEA). This consists of a set of real and imaginary stresses calculated at various frequencies and driven by a unit load.

This vibration-based analysis results in stress cycles with a zero mean stress.  DesignLife is also capable of superimposing the vibration loading onto a static offset such as a gravitational force or preload.

Additionally, thermal effects can be considered using multitemperature fatigue curves.  Temperatures can be constant across the whole model or they can vary if they were solved for in FEA.

2. Multi-axis, sequential, random excitation

 

Multiple single-axis random PSDs can also be run as a series of vibration fatigue analyses in DesignLife.  First the X-axis is excited for a prescribed time, then the Y-axis, then the Z-axis. This simulates the common electrodynamic shaker test where each direction is excited individually and sequentially. 

This virtual vibration fatigue analysis is also useful when evaluating a multi-PSD test conducted on a single axis. For example, it may be used to evaluate sequential tests of a single axis under different conditions.

3. Multi-axis, simultaneous, random excitation

 

Finally, simultaneous excitations from multiple directions can be analyzed by DesignLife.  This type of loading is often found in real world applications.  Just like the two scenarios above, a random PSD is used to describe the excitation of each direction.  Additionally, cross spectral densities (CSDs) are used to describe how each excitation interacts with the others. 

Thus, measured loads are first recorded in the time domain then converted into the frequency domain.

Ready to achieve success through failure prediction?