FEA 0402

Introduction to FEMAP Software

Overview of the Software

• The software being discussed is called Centa FEMAP, which is used by NASA. The speaker identifies as an aerospace mechanical engineer involved in international projects.

• Other simulation software exists in the market, but this training focuses on practical applications of finite element analysis (FEA), applicable across various platforms.

Importance of Understanding Software Functionality

• The speaker emphasizes that understanding the principles behind FEA allows users to apply knowledge across different software interfaces, likening software to a calculator where only the interface differs.

Initial Setup and Configuration

Configuring Units in FEMAP

• After downloading FMAP Nastran, users should navigate to 'File' and then 'Preferences' to configure measurement units.

• It’s crucial to set the scale factor correctly; if not configured properly (e.g., using meters instead of millimeters), it can lead to significant errors in analysis results.

Critical Steps for Accurate Analysis

• Users must ensure that their project settings match those from other design tools like SWK or Inventor, particularly regarding unit configurations.

Database Management and Backup Settings

Importance of Database Configuration

• The database feature acts as an automatic backup system that saves work periodically, preventing data loss during unexpected shutdowns or crashes.

Recommended Settings for Data Safety

• Users are advised to enable automatic backups and set a high number of undo levels (up to 90), allowing recovery from multiple stages without losing progress.

Conclusion and Next Steps

Future Learning Opportunities

• The session will be divided into two parts focusing on detailed configurations within FEMAP. This content aims to provide unique insights not commonly found in existing online resources.

FEMAP Configuration and Best Practices

Time Management and Data Positioning

• Discusses the importance of time-saving settings in FEMAP to prevent data loss, emphasizing the need for automatic saving configurations.

• Explains the recommended settings: a 30-minute interval or after every 125 commands, whichever comes first, to ensure model safety.

Visualization Preferences

• Introduces visualization controls within FEMAP, allowing users to set default views for models upon opening them in SolidWorks.

• Highlights the ability to save custom visualizations for future reference, enhancing presentation quality with formats like JPEG and PNG.

Performance Optimization

• Mentions dynamic scaling options that adjust view settings based on user preferences for better performance during modeling.

• Stresses the necessity of having adequate computer specifications (8GB - 16GB RAM) to handle complex analyses without lagging.

Graphics Settings

• Discusses graphical performance settings in FEMAP, noting that default configurations are usually sufficient but can be adjusted if necessary.

• Advises on disabling certain features like dynamic rotation when working with large models to improve simulation speed and efficiency.

Understanding Solvers in FEMAP

• Defines solvers as mathematical algorithms essential for computational calculations within finite element software like FEMAP.

• Provides insight into different solvers used by various software packages, highlighting Nastran's historical significance and its association with NASA.

Insights on Aerospace Software and Analysis

Overview of Aerospace Software Usage

• The speaker discusses their experience with NASA and various aerospace software, highlighting the importance of tools like MS Nastran and Femap Nastran in the U.S. aerospace industry.

• Emphasizes that while there are many software options available, such as FEMAP and ANSYS, they are all valuable for different applications within the aerospace sector.

• The speaker clarifies that their focus is not to criticize any software but to share personal experiences in aviation engineering.

Role of Engineers in Simulation

• Engineers play a crucial role in creating finite element models; it is not solely the software's responsibility to generate these models.

• Advanced technology allows engineers to predict project behavior under various loads before manufacturing, which is essential for safety and efficiency.

Importance of Solver Selection

• Discusses how solvers automate calculations, providing critical data such as stress factors and safety margins for engineering projects.

• The speaker mentions specific solvers used in industry projects, illustrating the variety of tools available for different simulation needs.

Integration of Software Tools

• Describes a scenario where Autodesk Nastran was requested for a project, showcasing flexibility in choosing appropriate software based on client needs.

• Highlights how FEMAP integrates with multiple solvers, allowing users to select their preferred tool easily during simulations.

Flexibility and Adaptability in Engineering Solutions

• The integration capabilities of FEMAP streamline workflows by automatically selecting solvers based on user input.

• Concludes with an emphasis on FEMAP's versatility as a powerful tool adaptable to various technical requirements across different projects.

Norms and Standards in Structural Analysis

Importance of Reliable Sources

• The speaker emphasizes the necessity of adhering to international standards, specifically mentioning MPPA10 as a guideline for reliable data sources in structural analysis.

• Using trustworthy sources is crucial; reliance on unverified information (e.g., Google) can lead to rejected analyses.

Following Established Norms

• When conducting structural simulations, it is essential to follow specific norms such as NBR 8800 for metallic structures or relevant ISO standards for aeronautics.

• The distinction between a mere "button pusher" and someone who understands theory and application is highlighted, stressing the importance of theoretical knowledge alongside practical skills.

Growth Through Knowledge

• Individuals who understand both theory and software applications experience continuous growth, while those lacking theoretical knowledge face limitations in their professional development.

• A reference is made to a professor who distinguishes between those content with easy tasks versus those willing to tackle challenging problems for personal growth.

Commitment to Learning

• The speaker encourages students not to settle for being just proficient users of software but rather strive to understand underlying principles deeply.

• The course structure includes both theoretical lessons and practical applications, aiming to cultivate top professionals in Brazil's engineering field.

Material Libraries and Configurations

• Students are advised on creating material libraries within their companies using various materials like IC20 or STM 36, which enhances project accuracy.

• Different types of elements (beams, solids, plates, shells) should be utilized appropriately based on project requirements; understanding these distinctions is vital for effective design.

Key Takeaways from the Session

• Important configurations discussed include file preferences and geometry settings that are foundational for successful simulations.

• The session concludes with an invitation for questions about configurations, emphasizing their significance in engineering practices.

Understanding Unit Systems in FEMAP Nastran

Importance of Unit Consistency

• The speaker emphasizes the critical nature of understanding unit systems in FEMAP Nastran, stating that it is foundational for finite element analysis.

• All examples throughout the training will exclusively use millimeters, tons, and seconds as units; mixing units can invalidate analyses completely.

Common Mistakes with Units

• A classic example involves a designer using SolidWorks to model a piece but failing to convert mass from kilograms to tons when performing structural analysis.

• When entering material properties in FEMAP, users must ensure they input mass in tons rather than kilograms; this conversion is crucial for accurate results.

Conversion and Its Implications

• The speaker illustrates that entering 200 kg directly into FEMAP without converting it to tons (0.2 tons) leads to significant errors in analysis outcomes.

• Emphasizing the importance of unit consistency, the speaker warns against using kilograms in FEMAP since all inputs should be in tons.

Key Units and Their Applications

• In engineering contexts, length should always be measured in millimeters, mass in tons, time in seconds, force in Newtons, and pressure/tension either in Pascals or Megapascals.

• The speaker clarifies that while Megapascals and Newton per square millimeter are equivalent measures of pressure/tension, it's essential to maintain consistent terminology.

Fundamental Principles of Analysis

• The principle of dimensional consistency is highlighted as vital for obtaining reliable results; discrepancies can lead to erroneous conclusions.

• A common error occurs when geometry data is mistakenly entered as kilograms instead of being converted into the correct unit system used by FEMAP (millimeters, tons, seconds).

Practical Application and Demonstration

• The speaker demonstrates how to define materials within FEMAP correctly by selecting options that align with the required unit system: millimeters for length and tons for mass.

• It’s reiterated that all mass entries must be converted from kilograms to tons before inputting them into FEMAP; failure to do so can result in incorrect weight calculations affecting modal analysis frequencies.

Consequences of Incorrect Units

• Not converting units properly can lead to severe inaccuracies such as explosive weight calculations or absurd frequency results during modal analysis.

Understanding Mass Conversion in Engineering Simulations

Importance of Unit Conversion

• The speaker emphasizes the fundamental rule that 1 ton equals 1000 kg, highlighting the necessity of converting kilograms to tons for accurate engineering calculations.

• An example is provided where a project mass of 25 kg converts to 0.025 tons, illustrating how to input this value into FMAP (Finite Element Method Analysis Program).

• Another example shows a mass of 480 kg converting to 0.48 tons, reinforcing the importance of correct unit conversion in simulations.

Common Errors in Mass Input

• A classic error is discussed where users mistakenly input mass directly in kilograms instead of converting it to tons, which can lead to significant inaccuracies in simulation results.

• The speaker warns against overlooking basic metric units and stresses that FEMAP operates with tons, not kilograms.

Consequences of Incorrect Measurements

• Misconfigurations or incorrect measurements can lead to errors that affect the entire project; even small mistakes can have large repercussions down the line.

• The discussion highlights the potential financial impact on companies producing millions of parts if errors occur due to improper simulations.

Understanding Simulation Results

• Viewers are encouraged not just to react to red indicators in simulations but rather analyze them critically; red does not always indicate failure points.

• The speaker advises against being overly focused on "red points," suggesting that failures may occur elsewhere due to factors like welding stress.

Analyzing Stress Points

• It’s explained that high-stress areas indicated by red do not guarantee breakage; other areas might fail due to hidden issues such as weld fatigue.

• Users are cautioned about misinterpreting simulation results without proper analysis and understanding, emphasizing the need for comprehensive evaluation beyond surface-level indicators.

Understanding Material Failure and Safety Factors

Key Concepts in Material Stress and Failure

• The speaker emphasizes that failure does not always occur at the critical stress points marked in red, highlighting the unpredictability of material failure.

• Red areas indicate regions of maximum stress; however, adjustments such as changing profiles or materials can mitigate risks without guaranteeing failure.

• The safety factor is defined as the yield strength of a material divided by the maximum stress experienced. This ratio helps assess whether a component can withstand applied loads.

Calculating Safety Factors

• An example calculation is provided: if a part experiences 200 MPa of stress and has a yield strength of 350 MPa, the safety factor is calculated to be 1.75.

• A safety factor greater than one indicates that the part can handle its load plus an additional margin (in this case, 75% more).

Importance of Simulation in Engineering

• The speaker notes that simulation involves more than just running software; it requires thorough preparation and understanding to avoid costly mistakes.

• Professionals must ensure accuracy in simulations to prevent financial losses for clients due to errors in project delivery.

Learning Opportunities and Expertise

• Participants are encouraged to engage with experts during sessions for deeper understanding, emphasizing the value of learning from experienced professionals.

• The speaker highlights their qualifications as an aerospace mechanical engineer, reinforcing the credibility of the knowledge being shared.

Common Errors in Unit Conversion

• A classic mistake discussed involves incorrect mass input; using kilograms instead of tons leads to significant calculation errors (e.g., entering 150 kg instead of converting it).

• Basic units are crucial for accurate calculations; derived units like area and volume must be understood within metric systems for effective engineering practices.