Description

Presentation Objectives. Talk about foundation of basic discontinuitiesIntroduce the limited component methodExplain how to produce a limited component modelReview past workPresent new workDiscuss potential outcomes for future workAnswer questions. What is a Structural Discontinuity?. A break or hole inside of a basic segment that adjusts its conduct under burden.

Transcripts

Limited Element Study of Structural Discontinuities Presented By: Ike Lee and Nick Lin Project Advisor: Ioannis Korkolis

Presentation Objectives Discuss foundation of basic discontinuities Introduce the limited component strategy Explain how to produce a limited component show Review past work Present new work Discuss conceivable outcomes for future work Answer questions

What is a Structural Discontinuity? A break or hole inside a basic part that changes its conduct under load

Examples of Structural Discontinuities Holes: Often used to help a aerospace structure or to bolt components together Cracks: Usually an aftereffect of material imperfections or regions of high stress

Concerns Uniform stacking of a square plate brings about a uniform anxiety circulation

Concerns Holes adjust the anxiety dissemination and prompt anxiety focuses. Investigation of Mesh Refinement EM 360 Fall 2002

Concerns Stress fixations at break tips Crack spread

Possible Consequences Stress fields around discontinuities can communicate with each other and cause disappointment. Cessna 402C Mishap Investigation , 1999

Solution Method Structural irregularity issues are frequently exceptionally hard to illuminate logically, now and then outlandish. Our strategy is to utilize ABAQUS, a limited component program.

The Finite Element Method (FEM) General system for developing estimated answers for limit esteem issues Study of Mesh Refinement EM 360 Fall 2002

How to Generate a Finite Element Model An information record must be composed containing the accompanying two sections: Model Data: This segment characterizes the geometry of the model and material properties. History Data: This bit characterizes how the model will be stacked and what qualities ought to be yielded.

Some Important Factors to Consider Boundary Conditions Load Type and Directions Mesh Refinement Study of Mesh Refinement EM 360, Fall 2002

Some Important Factors to Consider : Mesh Refinement Peterson\'s Stress Concentration Factors , 1997 11 Elements 1 Second K=4.342 s ____ max K= s Finite Element Study of Structural Discontinuities , 2003

Some Important Factors to Consider : Mesh Refinement 67 Elements 1 second K=4.41 Finite Element Study of Structural Discontinuities, 2003

Some Important Factors to Consider : Mesh Refinement 211 Elements 1 second K=4.47 Finite Element Study of Structural Discontinuities, 2003

Some Important Factors to Consider : Mesh Refinement 823 Elements 2 seconds K=4.512 Finite Element Study of Structural Discontinuities, 2003

Some Important Factors to Consider : Mesh Refinement Approx. 3000 Elements 4 seconds K=4.517 Finite Element Study of Structural Discontinuities, 2003

Some Important Factors to Consider : Mesh Refinement Approx. 19000 Elements 21 seconds K=4.520 Finite Element Study of Structural Discontinuities, 2003

Mesh Convergence Curve Finite Element Study of Structural Discontinuities , 2003

Computation Time Finite Element Study of Structural Discontinuities , 2003

Mesh Convergence Refining a coarse limited component work will bring about a more precise arrangement at the cost of calculation time.

Caveat and Approach Just on the grounds that an answer is gotten does not really mean it is right. Thusly, it is imperative to concentrate the outcomes and contrast your answer and a known, revise arrangement.

Previous Work Peterson\'s Stress Concentration Factors , 1997 Model 1 Finite Element Study of Structural Discontinuities , 2003

Previous Work Model 1 (proceeded) Finite Element Study of Structural Discontinuities , 2003

Previous Work Peterson\'s Stress Concentration Factors , 1997 Model 2 Finite Element Study of Structural Discontinuities , 2003

Previous Work Model 2 (proceeded) Finite Element Study of Structural Discontinuities , 2003

New Work Reduction of stress fixations from edges of gaps Finite component displaying of splits Reduction of break stress force consider

Reducing Stress Concentrations from Holes Method: Add another gap to lighten the anxiety focus. Constant: Radius of unique gap = 2 in Tensile Load = 1 psi in flat course Variables: R = sweep of included opening L = remove between focuses of gaps

Reducing Stress Concentrations from Holes Finite Element Study of Structural Discontinuities , 2003

Reducing Stress Concentrations from Holes Finite Element Study of Structural Discontinuities , 2003

Reducing Stress Concentrations from Holes Finite Element Study of Structural Discontinuities , 2003

Reducing Stress Concentrations from Holes Finite Element Study of Structural Discontinuities , 2003

Reducing Stress Concentrations from Holes Conclusion: Adding gaps in a plane opposite to the stacking heading does not decrease the anxiety fixation figure.

Reducing Stress Concentrations from Holes Finite Element Study of Structural Discontinuities , 2003

Reducing Stress Concentrations from Holes Finite Element Study of Structural Discontinuities , 2003

Reducing Stress Concentrations from Holes Finite Element Study of Structural Discontinuities , 2003

Reducing Stress Concentrations from Holes Finite Element Study of Structural Discontinuities , 2003

Reducing Stress Concentrations from Holes Finite Element Study of Structural Discontinuities , 2003

Reducing Stress Concentrations from Holes Finite Element Study of Structural Discontinuities , 2003

Reducing Stress Concentrations from Holes Finite Element Study of Structural Discontinuities , 2003

Reducing Stress Concentrations from Holes Conclusion: Adding openings in a plane parallel to the stacking heading reduces the anxiety fixation figure.

Finite Element Analysis of Cracks Crack design models: Tada The Stress Analysis of Cracks Handbook Model 1 Model 2 Model 3

Finite Element Analysis of Cracks Crack Model 1 (Center Cracked Plate)

Finite Element Analysis of Cracks Crack Model 2 (Edge Cracked Plate)

Finite Element Analysis of Cracks Crack Model 3

Finite Element Analysis of Cracks Tada, The Stress Analysis of Cracks Handbook Crack Model 3

Finite Element Analysis of Crack Repair Crack repair models: Finite Element Study of Structural Discontinuities , 2003

Finite Element Analysis of Cracks Center Cracked Plate with Stop Holes

Finite Element Analysis of Cracks Center Cracked Plate with an Array of Holes Near the Crack Tip

Finite Element Analysis of Cracks Patch Repair of Center Cracked Plate

Finite Element Analysis of Cracks Arrester Repair of Center Cracked Plate

Finite Element Analysis of Cracks Variation in Stress Intensity Factor with Arrester Strip Distance

Summary of Work Completed This Semester Used the FEM to decide how gaps and breaks influence stretch appropriations. Formulated a strategy to ease stretch focuses around openings. Explored break repair strategies.

Possibilities for Future Work Finite component demonstrating of auxiliary discontinuities under cyclic stacking Finite component displaying of basic discontinuities in more unpredictable structures Adaptation of scripting highlight in ABAQUS

Questions?