Scippy

    SCIP

    Solving Constraint Integer Programs

    Macros | Functions | Variables
    spring.c File Reference

    Detailed Description

    Coil Compression Spring Design model.

    Author
    Stefan Vigerske

    This example shows how to setup quadratic and nonlinear constraints in SCIP when using SCIP as callable library. The example implements a model for the design of a coil compression spring as it can be found in the GAMS model library: https://www.gams.com/latest/gamslib_ml/libhtml/gamslib_spring.html

    The task is to find a minimum volume of a wire for the production of a coil compression spring.

    Original model source:

    E. Sangren
    Nonlinear Integer and Discrete Programming in Mechanical Design Optimization
    Journal of Mechanical Design, Trans. ASME 112 (1990), 223-229

    Definition in file spring.c.

    #include <stdio.h>
    #include <math.h>
    #include "scip/scip.h"
    #include "scip/scipdefplugins.h"

    Go to the source code of this file.

    Macros

    #define nwires   11
     

    Functions

    static SCIP_RETCODE setupProblem (SCIP *scip)
     
    static SCIP_RETCODE runSpring (void)
     
    int main (int argc, char **argv)
     

    Variables

    static const SCIP_Real diameters [] = { 0.207, 0.225, 0.244, 0.263, 0.283, 0.307, 0.331, 0.362, 0.394, 0.4375, 0.500 }
     
    static const SCIP_Real preload = 300
     
    static const SCIP_Real maxworkload = 1000
     
    static const SCIP_Real maxdeflect = 6
     
    static const SCIP_Real deflectpreload = 1.25
     
    static const SCIP_Real maxfreelen = 14.0
     
    static const SCIP_Real maxcoildiam = 3.0
     
    static const SCIP_Real maxshearstress = 189000.0
     
    static const SCIP_Real shearmod = 11500000.0
     

    Macro Definition Documentation

    ◆ nwires

    #define nwires   11

    number of possible wire types

    Definition at line 61 of file spring.c.

    Function Documentation

    ◆ setupProblem()

    static SCIP_RETCODE setupProblem ( SCIP *  scip)
    		static

    sets up problem

    Parameters
    scipSCIP data structure

    Definition at line 93 of file spring.c.

    References deflectpreload, diameters, FALSE, M_PI, maxcoildiam, maxdeflect, maxfreelen, maxshearstress, maxworkload, NULL, nwires, preload, SCIP_CALL, SCIP_MAXSTRLEN, SCIP_OKAY, SCIP_Real, SCIP_VARTYPE_BINARY, SCIP_VARTYPE_CONTINUOUS, SCIP_VARTYPE_INTEGER, SCIPaddCoefLinear(), SCIPaddCons(), SCIPaddVar(), SCIPchgVarLb(), SCIPchgVarUb(), SCIPcreateConsBasicLinear(), SCIPcreateConsBasicNonlinear(), SCIPcreateConsBasicSetpart(), SCIPcreateConsQuadraticNonlinear(), SCIPcreateExprPow(), SCIPcreateExprProduct(), SCIPcreateExprSum(), SCIPcreateExprVar(), SCIPcreateProbBasic(), SCIPcreateVarBasic(), SCIPinfinity(), SCIPreleaseCons(), SCIPreleaseExpr(), SCIPreleaseVar(), SCIPsnprintf(), shearmod, TRUE, and y.

    Referenced by runSpring().

    ◆ runSpring()

    static SCIP_RETCODE runSpring ( void  )
    		static

    runs spring example

    Definition at line 426 of file spring.c.

    References FALSE, NULL, SCIP_CALL, SCIP_OKAY, SCIPcreate(), SCIPfree(), SCIPgetBestSol(), SCIPgetNSols(), SCIPincludeDefaultPlugins(), SCIPinfoMessage(), SCIPpresolve(), SCIPprintOrigProblem(), SCIPprintSol(), SCIPsolve(), and setupProblem().

    Referenced by main().

    ◆ main()

    int main ( int  argc,
    char **  argv 
    )

    main method starting SCIP

    Parameters
    argcnumber of arguments from the shell
    argvarray of shell arguments

    Definition at line 467 of file spring.c.

    References runSpring(), SCIP_OKAY, and SCIPprintError().

    Variable Documentation

    ◆ diameters

    const SCIP_Real diameters[] = { 0.207, 0.225, 0.244, 0.263, 0.283, 0.307, 0.331, 0.362, 0.394, 0.4375, 0.500 }
    		static

    diameters of available diameters (in)

    Definition at line 64 of file spring.c.

    Referenced by setupProblem().

    ◆ preload

    const SCIP_Real preload = 300
    		static

    preload (lb)

    Definition at line 67 of file spring.c.

    Referenced by setupProblem().

    ◆ maxworkload

    const SCIP_Real maxworkload = 1000
    		static

    maximal working load (lb)

    Definition at line 70 of file spring.c.

    Referenced by setupProblem().

    ◆ maxdeflect

    const SCIP_Real maxdeflect = 6
    		static

    maximal deflection (in)

    Definition at line 73 of file spring.c.

    Referenced by setupProblem().

    ◆ deflectpreload

    const SCIP_Real deflectpreload = 1.25
    		static

    deflection from preload (in)

    Definition at line 76 of file spring.c.

    Referenced by setupProblem().

    ◆ maxfreelen

    const SCIP_Real maxfreelen = 14.0
    		static

    maximal free length of spring (in)

    Definition at line 79 of file spring.c.

    Referenced by setupProblem().

    ◆ maxcoildiam

    const SCIP_Real maxcoildiam = 3.0
    		static

    maximal coil diameter (in)

    Definition at line 82 of file spring.c.

    Referenced by setupProblem().

    ◆ maxshearstress

    const SCIP_Real maxshearstress = 189000.0
    		static

    maximal shear stress

    Definition at line 85 of file spring.c.

    Referenced by setupProblem().

    ◆ shearmod

    const SCIP_Real shearmod = 11500000.0
    		static

    shear modulus of material

    Definition at line 88 of file spring.c.

    Referenced by setupProblem().