MSC.Fatigue--Professional fatigue simulation analysis software

At present, the simulation technology has been widely used in product design, finite element technology has become an indispensable important tool, according to the finite element obtained stress and strain results for further fatigue life estimation has been widely used. Compared with the traditional method based on the test, the finite element fatigue calculation can judge the fatigue life of the parts at the design stage, and the unreasonable life distribution can be avoided by modifying the design. Therefore, it can reduce the number of test prototype, shorten the product development cycle, thereby reducing development costs and improve the market competitiveness of enterprises.

MSC.Fatigue is MSC.Software company and the British Sheffield nCode International (nCode International) in close cooperation on the basis of the development of advanced fatigue analysis software. In the product design phase using MSC.Fatigue, fatigue analysis can be done before the design and manufacturing process, and an integrated life management to create an MCAE environment, a true prediction of product life, greatly reduce the production prototype and fatigue life test carried To the huge cost. MSC.Fatigue has made many of the world's leading companies and enterprises to obtain huge economic benefits. From the space station, aircraft engines to cars, railways, air conditioners, washing machines and other household electrical appliances to electronic communication systems, from ships to petrochemicals, from internal combustion engines, nuclear power, power plant equipment to general machinery manufacturing and other fields. Early fatigue analysis can improve product reliability, enhance customer confidence in product performance, but also reduce after-sales warranty and other costs, to avoid product recalls and other difficult to predict the serious consequences.

1 MSC.Fatigue featured

•  Fully integrated with MSC.Patran;

•  Support a variety of finite element software solution results;

•  Comes with a lot of material fatigue characteristics of the database;

•  Unique fatigue life under random vibration conditions;

•  Unique fatigue analysis of rotating wheels;

•  With heavy design cycle capacity, the real load conditions simulation;

•  Support MSC.Nastran all CWELD options-ALIGN, GRIDID, ELEMID, PARTPAT & ELPAT, 3-layer connection processing, support for XDB and .op2 files;

•  Windows-Unix unrestricted interactive communication;

2 MSC.Fatigue function module

2.1 MSC.Fatigue Pre & Post——Fatigue Life Analysis Preprocessors

Pre & Post integrated in the MSC.Patran environment before and after the fatigue analysis processor, can take full advantage of MSC.Patran powerful graphics capabilities, easy to establish fatigue life calculation model, and direct access to MSC.Fatigue all the analysis. The post-processing function makes it easy to visually and diagnose various fatigue life problems. Change the material and other fatigue input parameters, post-processing can be directly calculated under the new parameters of fatigue life, so the design model selection and optimization. Fatigue analysis process generally has five steps:

1) Enter the recycle material properties

2) input time-varying load (or frequency domain)

3) Enter geometric information (finite element stress or strain)

4) Perform a fatigue solution

5) Visualize the calculation of the results

MSC.Fatigue Pro / Post interface in accordance with the fatigue analysis of the process design, can effectively guide the user step by step to complete the fatigue analysis. At the same time can be very convenient to modify the input parameters to determine the fatigue sensitivity of the structure and optimize the design. Pre & Post can directly read the results of a variety of finite element software for fatigue life analysis, support the finite element software and file formats are:

•  MSC.Patran neutral file and external (unit, node, etc.) results file

•  MSC.Patran, MSC.FEA, MSC.AFEA results document

•  MSC.Nastran OUTPUT2 file, .xdb results file and bulk data files

•  MSC.Marc results file

•  ABAQUS results file

•  ANSYS results file

•  SDRC common file

MSC.Fatigue analysis results and input finite element results can be displayed in different ways, including:

•  FIG proportion ladder, cloud Ventura, contour maps and text reports include injury (linear and logarithmic scale), life repeating units, and user defined (linear and logarithmic scale), a safety factor, the biaxial parameter estimates

•  Residual degree, residual stress, scale factor sensitivity display

•  Fast graphics show the maximum damage area, the worst safety factor and the maximum biaxiality

•  Access material library, time history library, load history library

•  MPVXMUL - read up to 999 files

2.2 MSC.Fatigue Basic——full life and initial crack analysis

MSC.Fatigue Basic predicts the structural life of the structure according to the structural stress or strain distribution provided by the finite element model, the structural load change, and the fatigue properties of the material. The traditional S-N method can be used in the analysis, or a more modern local strain method (or initial crack method). The life-life method, commonly known as the stress-life method or the S-N method, does not strictly distinguish between crack generation and crack propagation, but gives a full life estimate before the failure of the structure. The initial crack method, ie, the initial crack model (or strain-life (ε-N) model), provides a basis for predicting the initial crack life of the product. The initial crack method and the full life method are common features:

•  Rain flow cycle count, matrix (bin) variable size (32,64,128)

•  Statistical redundancy parameter

•  Surface finish / surface treatment correction

•  Palmgren-Miner Linear damage accumulation, variable Miner accumulation (> 0, default is 1.0)

•  Custom life

•  Multi - axial stress state assessment

•  Safety factor analysis

•  Composition / Decomposition of Stress / Strain Tensor: Any Component, Principal Stress / Main Strain Maximum Absolute, Signed Von Mises Equivalent, Signed Tresca / Shear Equivalent

2.3 MSC.Fatigue Fracture——crack propagation analysis

MSC.Fatigue Fracture predicts the rate and time of crack propagation based on the finite element calculation results, the model structure shape, the structural load change and the fatigue properties of the material. The study of crack propagation often uses the traditional linear elastic fracture mechanics (LEFM). The crack propagation method has the following characteristics:

•  Minimum crack size of Kitagawa

•  Fracture toughness failure criterion

•  Mean stress correction

•  Cycle the cumulative rain flow cycle count

•  Initial and final crack length determination

•  Plane stress correction

•  Incision effect modeling

•  Hysteresis and closure effects modeling

•  Modified Paris Principle Based on Effective Stress Density Range

•  User custom life unit

•  Triangle solution of fracture mechanics (stress-stress density - crack length)

•  And NASA / FLAGRO2.03 graphical interface

•  Compression of stress / strain tensor: any component, principal stress / principal strain maximum absolute value, signed Von Mises equivalent, signed Tresca / Shear equivalent

2.4 MSC.Fatigue Utilities——advanced fatigue and loading function

The Utilities module contains advanced application applications that help MSC.Fatigue users collect, analyze, and process data such as measured values of stress or strain time history, and prepare for further MSC.Fatigue analysis. Its specific application can be divided into four categories:

•  Advanced load handling

•  Advanced fatigue analysis and display

•  File transfer

•  Drawing and printing

2.5 MSC.Fatigue Vibration——Vibration fatigue analysis

MSC.Fatigue Vibration predicts the fatigue life of structures or components under random vibration conditions. It is mainly used in vibration sensitive system, and the fatigue life of the structure can be estimated according to the stress power spectral density function (PSD's) or the transfer function obtained by finite element analysis. When using the transfer function, its function can be divided into stress response process and fatigue analysis of two parts. MSC.Fatigue Vibration contains the latest stress analysis tools, can give multi-load conditions, frequency domain problem solving method, but also contains the stress tensor migration and biaxial inspection of the latest developments.

2.6 MSC.Fatigue Spot Weld——Analysis of Fatigue Life of Spot Welding

MSC.Fatigue.Spot Weld Based on the finite element analysis, it is possible to predict the fatigue life of two metal plates at spot welding. In the calculation, the spot welding of the structure is regarded as the CWELD unit or the rigid unit connecting the two metal plates, and the metal plate is described by the thin shell unit. The method uses the force and moment of the cross section of the connecting element to calculate the stress at the weld, and then uses the S-N method to complete the life fatigue analysis of the structure.

With Spot Weld, we can accurately predict the fatigue life of spot welding, optimize the number and size of spot welding, thereby reducing manufacturing costs and increasing product reliability. Such as the car's body structure is usually thousands or even thousands of solder joints. In the production line, each robot can handle the number of spot welding is limited, due to the design of the solder joint layout is unreasonable, the result must be useless solder joints increase, and each additional solder joint means the cost of the production line An increase of $ 30,000.

2.7 MSC.Fatigue Wheels——Analysis of fatigue life of wheels

Fatigue analysis of wheels or other rotors can be performed using MSC.Fatigue Wheels, which are characterized by the propagation of the load along the periphery of the rotating body. Simulation is performed by applying a load to the continuous sector of the wheel. The definition of all load conditions in MSC.Fatigue uses "Loading", the user interface is very easy to handle, and uses stress results for each load case. Can draw the stress applied to the continuous sector of the wheel, the stress-history of each node on the wheel. By using the stress results of the load conditions, it is possible to determine a complete stress time history and fatigue damage for each node of the rotational change. Can be in the most serious damage to the surface angle for each node to draw fatigue life and fatigue damage cloud diagram, etc. show fatigue results. MSC.Fatigue Wheels Application:

•  All types of wheels or pulleys of transport.

•  Rotating machinery under cyclic loading.

2.8 MSC.Fatigue Multiaxial——multi-axis initial crack analysis

Unlike the commonly used uniaxial or proportional load conditions, MSC.Fatigue Multiaxial uses non-proportional, multi-axis stress state assumptions, and estimates the structural life through the crack propagation method to analyze the structural safety factor. Therefore, when the load is complex, the structure of non-proportional, multi-axis stress state, the algorithm can be very accurate fatigue life.

3 MSC.Fatigue support platform

MSC.Fatigue also has a wide range of platform applicability, can be HP / UX, SGI / IRIX, IBM / AIX / RS6000, Sun / Solaris, PC / Windows efficient operation.

4 MSC.Fatigue application example

Analysis of Fatigue Analysis of Chassis Components of a Car

Fatigue Life Analysis of Automobile Steering Joint in Chery Automobile Company

Analysis of fatigue life of aircraft landing gear