Hollow topology generation with lattices for computer aided design and manufacturing

A system comprising:

• a non-transitory storage medium having instructions of a computer aided design program stored thereon;
• and
• one or more data processing apparatus configured to run the instructions of the computer aided design program to
• obtain a design space for an object to be manufactured, a setup for physical simulation of the object, at least one design objective for the object, and at least one design constraint for the object,
• iteratively modify both a three dimensional topology of a generative model for the object and one or more outer shapes of the three dimensional topology using a generative design process that represents the three dimensional topology of the generative model as one or more boundaries between one or more solid regions and one or more void regions within the design space, wherein the iterative modification comprises:
• changing a constitutive model for the physical simulation in accordance with (i) a current iteration of the three dimensional topology and the one or more outer shapes of the three dimensional topology being offset inward to define an internal cavity of a hollow structure in the three dimensional topology and (ii) a homogenized lattice material representation that expresses stiffness of a lattice, which is composed of solid beams and lattice void regions, as a function of lattice topology and volume fraction for the lattice with a thickness of the beams in the lattice being uniform, performing the physical simulation of the object using the changed constitutive model to produce a physical assessment with respect to the at least one design objective and the at least one design constraint, computing shape change velocities for the one or more outer shapes of the three dimensional topology in the current iteration in accordance with the physical assessment, and updating the generative model for the object with the generative design process using the shape change velocities;
• adjust, after the iterative modification completes changes to both the three dimensional topology and the one or more outer shapes of the three dimensional topology, a thickness of the hollow structure, by changing the internal cavity, in accordance with the physical simulation, the at least one design objective and the at least one design constraint, while keeping the one or more outer shapes of the three dimensional topology constant;
• adjust, after the iterative modification completes changes to both the three dimensional topology and the one or more outer shapes of the three dimensional topology, (i) the thickness of the beams in the lattice, or (ii) a density of the lattice, in accordance with the physical simulation, the at least one design objective and the at least one design constraint, while keeping both the one or more outer shapes of the three dimensional topology and the adjusted thickness of the hollow structure constant;
• and
• provide a three dimensional model of the object in accordance with the three dimensional topology, the one or more outer shapes of the three dimensional topology, the adjusted thickness of the hollow structure and the adjusted lattice, for use in manufacturing a physical structure corresponding to the object using one or more computer-controlled manufacturing systems.

A non-transitory computer-readable medium encoding a computer aided design program operable to cause one or more data processing apparatus to perform operations comprising:

• obtaining, by a computer aided design program, a design space for an object to be manufactured, a setup for physical simulation of the object, at least one design objective for the object, and at least one design constraint for the object;
• iteratively modifying, by the computer aided design program, both a three dimensional topology of a generative model for the object and one or more outer shapes of the three dimensional topology using a generative design process that represents the three dimensional topology of the generative model as one or more boundaries between one or more solid regions and one or more void regions within the design space, wherein the modifying comprises
• changing a constitutive model for the physical simulation in accordance with (i) a current iteration of the three dimensional topology and the one or more outer shapes of the three dimensional topology being offset inward to define an internal cavity of a hollow structure in the three dimensional topology and (ii) a homogenized lattice material representation that expresses stiffness of a lattice, which is composed of solid beams and lattice void regions, as a function of lattice topology and volume fraction for the lattice with a thickness of the beams in the lattice being uniform,
• performing the physical simulation of the object using the changed constitutive model to produce a physical assessment with respect to the at least one design objective and the at least one design constraint,
• computing shape change velocities for the one or more outer shapes of the three dimensional topology in the current iteration in accordance with the physical assessment, and
• updating the generative model for the object with the generative design process using the shape change velocities;
• adjusting, by the computer aided design program after the modifying completes changes to both the three dimensional topology and the one or more outer shapes of the three dimensional topology, a thickness of the hollow structure, by changing the internal cavity, in accordance with the physical simulation, the at least one design objective and the at least one design constraint, while keeping the one or more outer shapes of the three dimensional topology constant;
• adjusting, by the computer aided design program after the modifying completes changes to both the three dimensional topology and the one or more outer shapes of the three dimensional topology, (i) the thickness of the beams in the lattice, or (ii) a density of the lattice, in accordance with the physical simulation, the at least one design objective and the at least one design constraint, while keeping both the one or more outer shapes of the three dimensional topology and the adjusted thickness of the hollow structure constant;
• and
• providing, by the computer aided design program, a three dimensional model of the object in accordance with the three dimensional topology, the one or more outer shapes of the three dimensional topology, the adjusted thickness of the hollow structure and the adjusted lattice, for use in manufacturing a physical structure corresponding to the object using one or more computer-controlled manufacturing systems.