Portland Community College | Portland, Oregon

Course Number:
CMET 121
Course Title:
Strength of Materials
Credit Hours:
Lecture Hours:
Lecture/Lab Hours:
Lab Hours:
Special Fee:

Course Description

Covers the relationship between stress and strain on deformable solids. Applies analysis to members subjected to axial, bending, and torsional loads. Covers combined stresses and properties of structural materials. Prerequisites: CMET 110, CMET 112, and (ENGR 102 or ENGR 105). Prerequisites/concurrent: CMET 123. Audit available.

Intended Outcomes for the course

Upon completion of the course student should be able to:

  • Analyze and design structural members subjected to tension, compression, torsion, bending and combined stresses using the fundamental concepts of stress, strain and elastic behavior of materials.
  • Utilize appropriate materials in design considering engineering properties, sustainability, cost and weight.
  • Perform engineering work in accordance with ethical and economic constraints related to the design of structures and machine parts.

Course Activities and Design

The lecture portion of the class will consist of the introduction of the engineering problem solving process, the conceptual material and interactive demonstrations of the engineering concepts.  The lab portion will consist of engaged, engineering problem solving in small groups.

Outcome Assessment Strategies

Individual, small group, and full class discussion; homework problems; examinations; and small group problem-solving sessions may be used to assess outcomes.
Lecture, homework, and in-class group activities will be coordinated.
Specific evaluation procedures will be defined during the first week of class. In general, grading will depend on weekly tests, homework, class participation, and a comprehensive final exam.

Course Content (Themes, Concepts, Issues and Skills)

  1. Strength of materials is the main foundation for both Mechanical and Civil Engineering in the upcoming design courses.
  2. Engineering design concepts are integrated into the Strength of Material course.
  3. Methods are learned for determining the stresses, strains and deflections produced in various members produced by applied loading.
  4. To provide training in a fundamental subject (mechanics and structural) necessary for careers mechanical, civil and related engineering fields.

The course work is based on the assumption of mechanical parts and structures are in static equilibrium"," The analysis is limited to the materials stressed in the elastic range.
Instructional Goal:
Develop an understanding of the concepts of stress and strain and their use in the analysis and design of machine members and structures.
1.1.0 Define direct normal stress and direct shear stress and compute their values.
1.2.0 Define normal strain and shearing strain.
1.3.0 Define proportional limit, elastic limit, yield strength, ultimate strength, modulus of elasticity, and Hooke€™s Law.
1.4.0 Describe ductile and brittle behavior of materials, emphasizing design implications.
1.5.0 Calculate design normal stress and shear stress for various metals and woods under various conditions.
Instructional Goal:
Develop an understanding of material behavior under a condition of pure torsion (twisting moment) on circular shafts.
2.1.0 Calculate shear stress distribution in solid and hollow round members under torsional loading conditions.
2.2.0 Design shafts for various conditions of power transmission and rotational speed.
2.3.0 Calculate angle of twist under torsional loading for determining the rigidity of the shaft.
Instructional Goal:
Develop an understanding of the models and procedures used in the analysis of transversely loaded beams and shafts with various support conditions.
3.1.0 Determine shear and bending moment diagrams for variously loaded and supported beams, using graphical calculus.
3.2.0 Calculate bending stress and shear stress at any location along the beam. Calculate maximum bending stress and maximum shear stress.
3.3.0 Determine the maximum deflection on statically determinate beams, using the method of superposition in reflection analysis.
3.4.0 Design beams based on allowable normal and shear stresses and maximum allowable deflection.
Instructional Goal:
Gain the ability to analyze the effect of various loading combinations on a mechanical/structural member.
4.1.0 Determine principal stresses, principal planes and maximum shear stress under various combinations of bending, torsion and axial loads on machine and structural parts using Mohr€™s circle.
Instructional Goal:
Develop an understanding of analytic methods used in connection with the structural design of columns, long mechanical members under compression.
5.1.0 Apply the Euler Equation to calculate axial buckling load for long straight columns of varying end conditions and materials.