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

scip	SCIP 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

argc	number of arguments from the shell
argv	array 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().