Methods and apparatus for predicting the failure of a component, and for determining a grain orientation factor for a material

A method, performed on a computer, for determining a grain orientation factor for a material, the method comprising:

• obtaining one or more equations that relate a stress direction to a slip direction for one or more respective potential slip systems of the material;
• simulating a grain orientation of said material, said simulating comprising, for each grain of a defined number of grains:
• using probabilistic methods to generate a slip plane normal angle for each of the potential slip systems in the grain;
• inputting said normal angles into said equations to obtain a potential orientation factor for each of the potential slip systems;
• and
• selecting the minimum potential orientation factor as a grain orientation factor for said grain;
• repeating said simulating for the defined number of grains thereby obtaining a plurality of grain orientation factors;
• creating a statistical distribution of said plurality of grain orientation factors to determine the grain orientation factor for said material and
• displaying at least the grain orientation factor for the material on an output device of the computer.

An apparatus for determining a grain orientation factor for a material, the apparatus comprising:

• a central processing unit (CPU);
• an output device for displaying at least the grain orientation factor;
• an input device for receiving input;
• and a memory,
• the CPU, memory, input device and output device being connected to one another via a bus, and the memory comprising:
• instructions for receiving input;
• instructions for obtaining one or more equations that relate a stress direction to one or more respective potential slip systems of the material;
• instructions for simulating the grain orientation factor of said material, said simulating comprising, for each grain of a defined number of grains:
• using probabilistic methods to generate a slip plane normal angle for each of the potential slip systems in the grain;
• inputting said normal angles into said equations to obtain a potential orientation factor for each of the potential slip systems;
• and
• selecting a minimum potential orientation factor as a grain orientation factor for said grain;
• instructions for repeating said simulating for the defined number of grains thereby obtaining a plurality of grain orientation factors;
• instructions for creating a statistical distribution of said plurality of grain orientation factors to determine the grain orientation factor for said material.

A method, performed on a computer, for predicting the failure of a component made from a material, the method comprising:

• obtaining a Finite Element Model (FEM) of a component;
• analyzing said FEM to obtain stresses at nodes of said FEM;
• identifying a subset of said nodes as significant nodes based on said stresses;
• determining a Representative Volume Element (RVE) for at least one of said significant nodes;
• developing an RVE microstructure-based failure model for at least one said RVE, said developing comprising:
• identifying a material microstructure in said RVE;
• characterizing how damage interacts with said material microstructure to provide at least one damage mechanism, wherein the at least one damage mechanism includes stress and fatigue;
• and
• creating a failure model for said material microstructure based on said at least one damage mechanism, said creating comprising:
• finding a sequence in which said at least one damage mechanism works to damage said material microstructure;
• getting for each said at least one damage mechanism one of a group of models consisting of:
• a crack nucleation model, a short crack growth model, and a long crack growth model;
• and
• linking said models to produce said RVE microstructure-based failure model based on information from said identifying, characterizing, and finding;
• simulating a component life using at least one RVE microstructure-based failure model, said simulating producing a result related to said component life;
• performing said simulating a plurality of times to produce results related to component life;
• preparing statistics using said results;
• comparing said statistics to a probability of failure (POF) criterion to determine whether said performing predicted failure for said component and
• displaying an indication of whether the failure was predicted on an output device of the computer.

A method, performed on a computer, for predicting the failure of a component, the method comprising:

• obtaining a Finite Element Model (FEM) of a component;
• analyzing said FEM to obtain stresses at nodes of said FEM;
• identifying a subset of said nodes as significant nodes based on said stresses;
• determining a Representative Volume Element (RVE) for at least one of said significant nodes;
• developing an RVE microstructure-based failure model for at least one said RVE;
• simulating a component life using at least one RVE microstructure-based failure model, said simulating producing a result related to said component life;
• performing said simulating a plurality of times to produce results related to component life;
• preparing statistics using said results;
• comparing said statistics to a probability of failure (POF) criterion to determine whether said performing predicted failure for said component;
• and
• displaying an indication of whether the failure was predicted on an output device of the computer.