BMW GS 97036 Dynamic Mechanical Analysis (DMA) on Polymers and Adhesives

The “BMW GS 97036 Dynamic Mechanical Analysis (DMA) on Polymers and Adhesives” standard, developed by BMW, a multinational vehicle manufacturer, describes the requirements and test procedures for performing dynamic mechanical analysis (DMA) or dynamic mechanical thermal analysis (DMTA) on polymeric materials, elastomers, plastics, adhesives, and related components used in BMW vehicles.

Dynamic mechanical analysis (DMA) is a widely used materials testing technique that measures the viscoelastic properties of a material as it deforms under periodic (oscillating) stress. Performed by applying a sinusoidal force (or stress) while varying temperature, frequency, or time, the test reveals the following fundamental properties:

• Storage module: Represents the elastic (stiffness) component.
• The modulus of loss represents the viscous (energy-dissipating) component.
• Loss factor: The ratio of the loss modulus to the storage modulus indicates damping behavior and transitions such as glass transition temperature.

These properties are critical for automotive applications because polymers in vehicles must withstand temperature fluctuations, vibrations, mechanical loads, and environmental influences while maintaining their performance (e.g., in seals, interior trim, adhesives, damping elements, hoses, or fasteners).

The BMW GS 97036 standard is closely aligned with international norms such as the “ISO 6721 Plastics – Determination of dynamic mechanical properties” standard developed by the International Organization for Standardization (ISO).

Test methods typically involve tensile, compressive, shear, bending, or torsional modes. Torsion is frequently mentioned in laboratory descriptions for BMW qualification tests. Typical measured parameters include:

• Glass transition temperature
• Temperature-dependent modulus curves
• Damping behavior
• Secondary transitions
• Fragility or softening points

Material adequacy is used for incoming goods inspection, defect analysis, and approval of polymer compounds (e.g., EPDM rubber seals, interior plastics, structural adhesives) from suppliers.

Many independent testing laboratories offer authorization or accreditation to perform testing according to the BMW GS 97036 standard. This is part of BMW’s supplier quality assurance process, and materials must meet this standard to be approved for use in production tools.

Material data sheets for compounds such as flame-retardant EPDM or other elastomers often list compliance with this standard, citing values ​​such as glass transition temperature values ​​around minus 64 degrees for specific low-temperature classes.

The BMW GS 97036 standard is necessary because modern vehicles rely heavily on polymeric materials (plastics, elastomers/rubbers, adhesives, composites, damping elements, seals, interior trim, hoses, fasteners) that must function reliably under a wide range of demanding real-world conditions.

Unlike simple static tests (e.g., tensile strength at room temperature), dynamic mechanical analysis (DMA), the method described in this standard, provides critical information about viscoelastic behavior as a function of time, temperature, and frequency. This directly addresses fundamental challenges in automotive engineering and reliability.

The main reasons for developing and implementing this standard are as follows:

• Extreme temperature variations in vehicle operation: Vehicles experience large temperature fluctuations: for example, the engine compartment reaching at least 120-150 degrees, the underbody and exhaust areas becoming very hot, and the interior reaching temperatures from -40 degrees (cold start in winter) to +80-90 degrees (cabin left in the sun in summer). Many polymers undergo dramatic changes near the glass transition temperature. Below the glass transition temperature, they become brittle, and above it, they become soft and sticky. Dynamic mechanical analysis (DMA) precisely determines the glass transition temperature, secondary transitions, and the usable temperature range, preventing unexpected failures (seal cracking in winter, sagging of interior parts in hot weather).
• Vibration and dynamic loads: Engines, drivetrains, road inputs, and chassis vibrations subject components to cyclical loading over a wide frequency range. DMA defines the following values:
• Storage module (rigidity under dynamic conditions)
• Loss modulus and loss factor (damping/energy dissipation)

This is essential for NVH (noise, vibration, harshness) performance, durability of vibration isolators and fasteners, adhesive bonds under fatigue, and prevention of resonance problems.

• Long-term durability and aging: Polymers degrade over time due to heat, UV, ozone, chemicals (oils, fuels, cleaners), moisture, and mechanical stress. Dynamic mechanical analysis (DMA) detects early changes in the module or glass transition temperature shift after aging/weather exposure tests, allowing BMW to predict the vehicle's service life and prevent warranty issues (e.g., leaking seals, rattling interiors, adhesives failing after 5-10 years).
• Safety-critical and functional performance: Examples of components tested under this standard include:
• Engine mounting elements and transmission mounting elements (must isolate vibration without collapsing at high temperatures).
• Door seals / airtight strips (EPDM, TPE) (remain flexible at -40 degrees to prevent water ingress / noise).
• Structural adhesives (maintaining adhesive strength at impact-related temperatures and under dynamic loads).
• Interior plastics (prevent creaking, deformation, or brittleness).
• Damping layers (e.g., in ceilings, floors) (effectively control noise across varying temperatures).

A material that appears acceptable in static tests may produce poor results in real-world use if its viscoelastic properties fall outside acceptable limits.

• Supplier consistency and quality assurance: BMW sources materials from numerous suppliers globally. This standard standardizes the test protocol (mode, heating rate, frequency, sample geometry, etc.), ensuring comparable results.

In short, static mechanical tests alone are insufficient for polymers in the automotive environment. Dynamic mechanical analysis (DMA) provides BMW with the data needed to select, qualify, and control materials that deliver safety, comfort, NVH quality, durability, and low warranty risk.

In conclusion, the BMW GS 97036 standard is a specific material testing specification that helps ensure the reliability and durability of plastic and rubber components in BMW automobiles. This standard is an important reference for characterizing viscoelastic behavior under realistic operating conditions.

For many years, our organization, with its competent and experienced team, has been understanding the needs of its clients, providing the advanced testing services they require, and assisting them in the establishment, implementation, and improvement of management systems. Within this framework, we also provide testing services in accordance with the BMW GS 97036 standard.