FEMFAT--high-end fatigue strength and optimization analysis software

FEMFAT is a set of engineering-oriented fatigue strength analysis and optimization software, cohesion of years of practical experience in engineering development, and through the use of global users to verify that the algorithm is efficient and accurate, reliable results. The software considers a variety of fatigue strength factors, the greatest degree of true reflection of the actual component of the force state, to provide a credible analysis and prediction results, to facilitate engineers in the early stages of product design and evaluation, thus accelerating product development Process, reduce product development costs, improve product development quality.

Module function

BASIC module: Simple single—axis fatigue life analysis in load spectrum form;

Femfat Basic is the Software Foundation module, it and other large amount of finite element software such as Nastran, Abaqus, Ansys, I-Deas, Medina, Patran, pro/mechanical and so on have the friendly software interface. In order to be more effective and convenient to integrate into the user's CAE project, some common user interfaces such as Adams, Simpack, Tosca, RPC, Lms-tecmath, diadem and so on are integrated into the FEMFAT.

• Reliable and effective analysis of the results of the FE analysis method;

• With the common finite element software interface;

• The fatigue behavior is calculated for the simple load conditions where the principal stress direction is constant;

• Fatigue damage analysis can be performed using the load spectrum created by ladder, rain flow matrix and synthetic method.

• Fatigue factor analysis of fatigue limit;

• With more than 350 different materials database (steel, cast iron, aluminum and magnesium alloy);

• Consider a number of factors that affect fatigue strength.

PLAST module: consider the occurrence of plastic deformation fatigue life analysis;

Local plastic deformation will occur when the local stress exceeds the yield limit of the material. This plastic deformation will be considered in the FEMFAT PLAST module.

A stress load spectrum describes the amplitude and the number of cycles of vibration stress, which occur in the use of components. A load spectrum does not contain information about the order of individual stress cycles. Therefore, in FEMFATPLAST, the effects of local stress and order will be used to approximate the "favorable" and "unprofitable" order.

After a linear stress from the finite element analysis, a cyclic stable stress-strain curve will be used to calculate the elastic-plastic stress. In the first step, the maximum stress will be calculated from the Neuber hyperbola. In the next step, the minimum stress for the reverse cyclic elastoplasticity will be determined.

When the influence of the order is considered, depending on the magnitude of the average stress, the local damage values of the entries in the rainflow matrix will be superimposed. The reoriented stress of the previous entry will be passed to the next calculated entry. The units in the rainflow matrix that depend on the average stress of the compression are different from the units that rely on the average stress of the tension.

BREAK module: static overload analysis;

The user can select this method when the user is interested in predicting the nodes of the model due to the high stress gradient generated by the linear calculation. This means that FEMFAT BREAK is not a fatigue analysis project, but it is a very useful tool based on the results of linear analysis to try to reduce the number of trials required for different design options.

FEMFAT BREAK Consider the relative stress gradient in the model to determine the stress limit. FEMFAT can determine the Neuber stress limit of the material by the properties of the material (fracture stress and Young's modulus) and the application of Neuber hyperbola. This is the information of the maximum allowable stress relative to the relative stress gradient, which is obtained by the tensile stress generated by the pull and pressure of the test rod.

HEAT module: Thermal fatigue analysis taking into account temperature effects;

The FEMFAT HEAT module is intended for low-cycle fatigue analysis of components under mechanical and thermal shock conditions. In particular, engine components such as cylinder heads, pistons, exhaust manifolds, turbine blades, etc. must meet the design requirements for economic and fatigue durability.

At present, as the requirements for engine weight, performance and emissions continue to increase, engine components and exhaust manifolds will be subject to greater loads and higher temperatures. So that parts in the high temperature and pressure at the same time under the action of fatigue life is particularly important. At present, the prediction of thermomechanical fatigue is more and more concerned by engineers, who try to simulate by the situation of isothermal and single repetitive load conditions. However, the isothermal test does not obtain the full damage mechanism under constant strain and temperature conditions. As Professor Sehitoglu puts it, under the thermomechanical conditions, we should have a deep understanding of the microscopic mechanisms that affect the different properties of the material.

• Stress and strain calculations based on elasto-plastic deformation (eg analysis by ABAQUS)

• Provides user interface for NASTRAN-OP2 and ABAQUS-FIL transient node stress and strain

• The user interface of the transient node temperature

• Time information of the user interface

• Thermal shock fatigue database

EHD module: bearing analysis, analysis of bearing oil film pressure;

NVH module: acoustic analysis, consider the structural fatigue changes caused by external excitation such as sound;

FEDIS module: the main function is to provide a variety of finite element before and after processing software interface;

WELD module: Fatigue analysis of seam welding;

Welding parts will greatly reduce the ability to withstand dynamic loads. Therefore, the finite element analysis of welded parts is a very important issue for CAE. In order to solve this problem, the automatic assessment of weld dynamic loads has been developed and integrated in the FEMFAT WELD module.

• Viable welding unit meshing

• Automatic Identification and Evaluation of Welding Unit

• Open welding database:

• Groove coefficients, S / N curves, Haigh graphs and thickness effects

• Visualization results: damage value, life and safety factor

• Compatibility: BASIC & MAX

SPOT module: spot welding fatigue life analysis;

The FEMFATSPOT module is used to analyze the stiffness and fatigue of solder joints and self-piercing rivet parts. The results of the analysis can be displayed using generic finite element postprocessing or FEMFAT VISUALIZER.

• Automatic detailing of the cell grid

• Compatibility with general FE systems

• Improved stiffness simulation

• Based on test results simulation

• New Soldering Technology Application and Extension (Spot-welding, Self-piercing riveting)

• Automatic identification, identification and evaluation of solder joint area

• Open spot welding database: spot diameter, S / N curves, Haigh Diagram

• Graphical results

• Compatibility with other modules: BASIC & MAX

STRAIN module: true fatigue life analysis, using the measured stress / strain results to analyze fatigue life;

The STRAIN module will extend the range of FEMFAT fatigue analysis software by adding additional functionality to process the measurement data. The strain gauge data measured using the strain gauges can be stored by the FEMFAT LAB and other data processing software and provided in the appropriate format for STRAIN.

The STRAIN module provides two main functions and is thus divided into two sub-modules.

• The STRAIN CALC submodule can be used to perform damage analysis and to determine the fatigue safety factor. Similar to the analysis in Trans MAX, but in this case the analysis is based on the measured strain value. There is no need for a finite element model for this analysis.

• The STRAIN COMP sub-module is used to compare the data calculated by the finite element and the measured data. Both the stress and the strain data can be used in the analysis.

MAX module: multi - axis fatigue life analysis;

It is not appropriate to use simple methods such as equivalent uniaxial forces to study the effects of multi-axial stresses on complex components such as white bodies, chassis components, girders or crankshafts.

The FEMFAT MAX module was developed to evaluate and evaluate these complex load conditions in an accurate and efficient manner. These methods are derived from appropriate literature (eg, FKM specifications), their own development, and long-term research and engineering tests.

• Reliable and effective analysis of complex loads;

• And MBS and measurement data system interface, access to the load history data;

• Able to handle channel (Channel) and transient (Transient) load conditions;

• By setting the filter to improve the efficiency of the calculation;

• No load limit;

• Compatible with WELD and SPOT

LAB module: load signal processing. Including load of rain flow analysis, waterfall analysis;

The FEMFAT Lab module combines the road test, the bench test and the computing department organically. It is a powerful tool for a large number of data can be observed and processed. FEMFAT Lab in a few seconds can display millions of scanning points or hundreds of channels of time course. Abnormal such as drift, average displacement and sharp points can be removed automatically or manually. Application of FEMFAT Lab module "project logic" can save a lot of operating time, because the same operation of different files can be completed automatically.

The FEMFAT Lab contains the following subcomponents:

LAB Time

• statistics

• (X-t or x-y), the editing of the time domain (cropping, moving, moving, zero)

• Filter - contains mathematical and logical formula editors, integers and differentials

• Moving average, center signal - finding and changing errors in measurement data

• Merge and extract channels

• File add

• Data format conversion

• Filter signal

• Modification of measurement parameters

• text editor

LABFrequency

• Road spectrum analysis: power spectrum, transfer equation, cross spectrum and so on

• Convenient parameter evaluation

• Rain map

• Campbell Chart

LBClass-Fatigue

• Rain flow calculation, layer crossing method, ranks counting method

• Multidimensional rain flow calculation

• In the layer classification time can reach 3 dimensions

• (X-t or x-y), the editing of the time domain (cropping, moving, moving, zero)

• Rain stream matrix editor

• The addition of the classification results (subtraction)

• Fatigue analysis according to the Miner method

• Life assessment

• Load the equivalent data for the damage values of the FE and the test bench

LAB VI (VirtualIteration)

• Virtual iteration is based on a model in the time domain using multi-body dynamics simulation of the external excitation to determine.

• By applying a simulated iterative process similar to the actual physical bench test, you can adjust the external load on a component. This approach can be achieved by making the internal measurement (that is, the appropriate load flow) can be regenerated (a solution to the inverse nonlinear problem) when the desired accuracy is achieved.

Visualizer module: Fatigue results post-processing. Generate reports, life cloud map, damage cloud map and so on.

FEMFATVISUALIZER is a fast 3D post-processing to show the structure of the finite element model and the results of the analysis. It is also possible to display the corresponding finite element stress distribution in the FEMFAT BASIC, Trans-MAX and Channel-Max modules. The stress generated by the load overlap for the Max module can be displayed. You can observe all channels or exclude some channels.

FEMFAT advantage

• For the project development of the special fatigue analysis solutions, the world more than 1,000 users of the successful verification and engineering practice;

• FEMFAT software and other FE software has a very good integration, simple operation, easy to learn and use;

• After years of project cooperation and product development, ECS has accumulated a lot of data and experience in product structural strength analysis, and can establish a set of systematic process of structural strength analysis, evaluation and optimization according to user's needs.

• ECS is a professional automotive development technology engineering center, a world of first-class professional product research and development of the application team and first-class infrastructure strength laboratory, FEMFAT software functions are constantly expanding and enhancing the rapid response to the new needs of users.